Moment of Clarity rage power lets you cast while raging.
You can't cast with Urban Barbarian. It spells out what changes from regular rage to controlled rage and casting isn't among the changes.It's not that clear. Expect table variation.
I mean, it doesn't spell out "you CAN'T cast" in Core Barbarian, and it doesn't spell out "you can cast" in Urban Barbarian, so...yeah.
It's a well accepted that the line "any ability that requires patience or concentration" is what disallows casting during a rage. Since Controlled Rage does not overturn that statement...
The best is probably Oracle, specifically a Juju oracle but Bones can work pretty well too. Cleric's not a bad choice either, a bit boring but it gets the job done without much fuss. If you don't mind being evil and more martial focused, Anti-paladins make decent necromancers as well. The primary things you are looking for are the Animate Dead and Desecrate spells, which makes divine spellcasters slightly more suited to being dedicated necromancers. Keep in mind that raising dead is not a cheap business, and you will often be strapped not only for gold, but corpses as well.
Haven't tried an oracle necromancer but definitely cleric over sorcerer.
Melee necromancers are better of cleric than sorcerer. Turn undead, higher bab, bigger hit die an no arcane spell failure are all things you want. Battle cleric with undead domain and the channel smite feat lets you change the leftover channels you haven't used on command undead to either smite for damage or channel negative for party healing. In my xp channeling for damage is a waste of your action. Then use the second domain for damage: war, ferocity, demon, strength or destruction come to mind.
There are 3 basic kinds of necromancer. The answer depends upon which kind he wants to be.
Undead General - Probably oracle with cleric a very close second. Though the wizards and sorcs have a few neat spells for this that some people prefer. This is fairly powerful, but a lot of work and organization to keep track of all you dead minions. I usually would not recommend this one if you are not an experienced, knowledgeable, and organized player.
Casting hurt spells from a safe distance - Examples include Enervation and Fear. Wizard or Sorc can both do very well at this. While it doesn't usually win fights all by itself, this is a fairly easy style to put a lot of serious debuffs on the opposition. Then let your allies beat them to a pulp.
Beating up on things in melee and using touch range hurt spells - Cleric with Oracle second choice. Some people really like this because some of the touch range spells are the nastiest available. Spells like Contagion and Bestow Curse are awful/awesome to have. Combined with negative channeling and variant channeling, you can make things much easier to bash with your morning star.
Probably the easiest of the 3 to run. If you are not sure which/if spell to use, you can always swing a weapon.
Decide which one you want then look through the online guides. There is a guide for almost anything you could want to build.
I like the wizard necromancer, and Think it is worth a look. Ravindork have a quite amazing necro juju oracle on his build list somthing i dont remember her name.
Also the shaman looks like it could make a amazing and versatile necromancer.
The dragon disciple thing made me think it had to be capable of melee, if not then a focust build is way better (battle necromancers are mad as hell). For a battlecleric it is really enjoyable to be a frontliner and have your own meatshield and flanking buddy so it is stil a valid option. If you don't have to go in melee then having to have at least 15 points on strength is a waste and I would go wizard, cleric or if allowed juju oracle and move the points in strength to you caster or charisma score.