|Sam Phelan Customer Service Representative|
Occultist (if it is allowed in your campaign) is technically not a full caster.
Other than that, Use Magic Device is probably your best bet if you need to do this on demand, leaving aside more obvious choices like having a fellow party member learn it or taking Leadership. If you don't need it on demand, in many campaigns it shouldn't be too difficult to find spellcasting services.
Edit: A complication is that greater make whole is required in many cases, and that spell is only available if your GM is okay with using stuff from the Technology Guide. Without that spell, you need a much higher level caster to repair a given item.
Salamander Bloodline Bloodragers get make whole as a bloodline spell.
Otherwise, Deific Obedience [Brigh - Sentinel] can give you make whole as a spell-like ability. With Versatile Obedience, you can get this at 10th level.
A Paladin with Oath Against Grotesquery gets make whole added to their spell list too.
Otherwise, play a Wyrwood with the Repair Magic alternate racial!
The problem is gaining GREATER Make Whole.
Best way around that I can think of is going Fighter into Heritor Knight PrC. You'd get Greater Make Whole 1/day at 11th level, and your Weapon Training stacks.
As for increasing caster level, the Transmuter of Korada is the best trait for increasing CL in our case.
Spell Specialization has some steep requirements, but maybe we can dip a class to get a Spell Focus bonus feat. Wizard would be a good 1-lvl dip, because it grants access to Knowledge is Power (arcane discovery) and the PFS rule allows wizards to take Spell Focus as a bonus feat instead of Scribe Scroll.
The orange ioun stone is really expensive, but you can just pressure the party caster to buy it and borrow it from him whenever you need it. With a way finder, you can get up to +4 CL with a couple tries.
Elves can get Spell Focus for free as well, which qualifies for Spell Specialization.
Illustrious Urbanite trades away keen Senses (+2 Per)
Overwhelming Magic trades away elven magic and weapon familiarity.
Half-Elf is probably better though, because you can use the Skill Focus to qualify for Heritor Knight (you need Skill Focus by level 5, you only need Spell Specialization at level 11) and the Spell Focus will stack with the racial bonus.
The 1/day Greater Make Whole is enough, because you'll use it on the big things. But the regular Make Whole will also be used for less important things (although maybe you can rely on the party caster).
Heres' the full list of what I found for traits
Transmuter of Korada gives all transmutation spells +1 CL, and 1/day Extends one type of "+4 to a stat" spell.
Gifted Adept, Inspired by Greatness, and Secret of the Impossible Kingdom grant +1 CL for one specific spell.
Outlander gives +1 CL to three spells (all arcane, or all divine), and a knowledge skill bonus
Shaper of Reality grants +1 CL to any conjuration or transmutation spell, once per day.