It's 2:38 AM, and I really shouldn't be thinking about build ideas, but...
What about a Crossblooded Orc / Psychic Sorcerer? It seems ridiculously synergistic from my point of view (at least considering how Crossblooded cripples you), I mean:
#1: Psychic casting = no arcane spell failure = armor all day.
#2: Blood Havoc + Orc Bloodline Arcana + Harrow Chosen Trait = ow Mind Thrust - or grab Spell Focus (Whatever) off your Bonus Feats list to make it more generally applicable.
#3: The 3rd level Orc ability, Fearless, gives immunity to fear effects as you level - no more psychic casting being shut down by a mere intimidate check!
#4: Undercasting Prodigy gives you access to higher level spells to use your higher level spell slots, that you normally wouldn't have access to as a result of crossblooded.
#5: Having access to no arcane spell failure (and thus being reasonably well protected), you could maybe put the level 9 / 15 Orc bloodline abilities to work? This is more of a stretch, but...
I suppose it could be argued whether any of these bonuses together (if they even work the way I want to, at least it is my reading that the Crossblooded Sorc gets access to higher level spell slots as he levels, he just doesn't know any spells to use them with w/o metamagic) make up for the inherent loss of spells, saves, and progression that is the cost of the Crossblooded archetype, or whether or not it's simply better off with Eldritch Heritage (Orc) - it is at the very least an amusing thought.
Any forseeable snags that you fine folks can locate?
Look up bloodline mutations.
The first one lets you trade out a first level bloodline power for +1 damage to all damage dice for sorcerer spells.
Bear in mind that there are spells and effects than fear which can shut you down and you just volunteered for a -2 to your will save. OK, they're relatively rare, but don't get cocky.
I'd really rather have the 9/15 psychic bloodline abilities than the orc ones and you have to choose one or the other. This is especially true about the orc bloodline ones with the +10 DC to casting defensively much of the time. I think you're right about how undercasting prodigy would work, too, which makes it that much more attractive.
Look up bloodline mutations.
The first one lets you trade out a first level bloodline power for +1 damage to all damage dice for sorcerer spells.
It's a wonderful ability, isn't it? :)
OP: Good find! I agree that there does seem to be some synergy...even though my first thought was why would anyone do crossblooded orc without also doing draconic.
Thanks! Fair point in regards of xBlooded - I guess this is my attempt at making a sorcerer that doesn't compensate for his impure blood by taking a 19 level dip in Wizard to prove himself the superior mage. :) I'm hoping that getting +1 damage on spells from Orc and +1 from Blood Havoc (like NoTongue mentioned) will make up for not going Draconic, so provided I choose Spell Focus (Evocation) at some point, I'll be able to toss around stuff like 10d6+20 fireballs (sure, it's not 10d6+30, but prior to Magic Tactics that seemed like a perfectly acceptable thing).
And there's something about being able to deliver ridiculously powerful Mind Thrusts that keep upgrading over the levels. 5d6+10 is pretty neat at level 3, but level 9 is really looking like the golden level, where both Undercasting and Fearless kick in.
Bear in mind that there are spells and effects than fear which can shut you down and you just volunteered for a -2 to your will save. OK, they're relatively rare, but don't get cocky.
I'd really rather have the 9/15 psychic bloodline abilities than the orc ones and you have to choose one or the other. This is especially true about the orc bloodline ones with the +10 DC to casting defensively much of the time. I think you're right about how undercasting prodigy would work, too, which makes it that much more attractive.
I completely agree that the 9/15 psychic abilities are far more desirable, Undercasting Prodigy is a bare-bones necessity for my line of thinking, there's no way I'd willingly swap that out, I was more contemplating whether it might have been worth it to get the inherent +6 Strength / the power to grow large @ L15 in place of getting Blindsight 30... yeah, no. I blame that on my tired mind :P
In regards of shoring up bad saves, I'm thinking either Half-Elf or Half-Orc - HOrc would be thematic (and would allow me to swap out Darkvision since you get it from the Orc Arcana), and the Psychic Bloodline offers Iron Will as a bonus feat, so I'm figuring that's a #1 pick at level 7.
More things to consider:
VMC - do or don't?
The obvious one is to go VMC Battle Oracle to get Heavy Armor Proficiency at level 3 (not like you can afford full plate before that anyway) and thus walk around armored. A few curses seem like they would have different merits;
§1: Wolf-Scarred literally has no drawback anymore, beyond what your character looks like - but a bite attack isn't the most jaw-dropping benefit to a sorcerer either.
§2: Covetous pretty much is the new "casting" curse - but doesn't offer anything at all to a sorcerer until level 10 (+4 to UMD, woo!) with the level progression, which makes it not too appealing
§3: Legalistic is a boring, if generally applicable curse.
§4: HORROR REALMS CURSES! Two come to mind, of sorts.
->>> Deep One: Tank a -5 to your land speed, gain a swim speed = land speed. Neat for the guy in armor, and with a 25 base speed, you get reduced to 20' in medium/heavy armor - which is exactly what you'd get from being in heavy armor with 30' speed. Score! Level 5 benefit progresses into a further +1 to NA (by the wording, it should stack with the Orc bloodline natural armor), +1 caster level whenever casting underwater and on [water] spells (L10) and finally, permanent Freedom of Movement underwater as a capstone.
->>> Hellbound: Oh boy. You can't cast [chaotic] or [good] spells, and take a -4 penalty on Diplomacy checks versus good and chaotic creatures. Get +2 to Bluff & Intimidate at level 1, +4 versus charm effects at L5, and maybe the most fun - immunity to fire at level 10. (Those xd6+2x fireballs? Fireball yourself for fun and profit.). Tops off by making any weapon you hold lawful and evil at level 15 (so, level 20 for you). Eh.
The alternatives consist of either buying the armor feats the old fashioned way through level progression, go for the classic Armor Expert + Mithral Breastplate combo, or sidestep the whole ACP to initiative issue by getting Noble Scion (War).
That being said, I do find VMC Oracle (Battle + Deep One) to be humorously synergistic, since you can grab Create Water at level 7, and dig a ditch before casting long-duration spells, thus getting the +1 CL on your buffs. Being a psychic caster, you won't have any issues with underwater verbal components either. :)