In regards to working on the jeep, if you have the tools, there's not a whole lot you can mess up. These tasks can be done with simple hand tools (Although impact wrenches are handy), floor jack, jack stands, torque wrench, and possibly a measuring tape.

As you are kind of figuring out, shops are really hit and miss with this stuff. There are some quality shops out there, but I'd submit they are fewer and far between all the supposed 4x4 shops that aren't worth their salt. You have a bigger build in it's current form, and it's going to require a bit of work and understanding. 3.5" lift with 37s, PR60/44s is a bigger commitment than 2.5" lift with 35's. You kinda cross a threshold especially if you are going to use the jeep to the build's extent and not just look at it.

There is very little that you should not be able to accomplish on this jeep with your own efforts. Even if you don't have the knowledge, the information is out there. The help is here. People are willing to, as much as possible, hold your hand through some of this stuff. Often times if you don't have the tools, the cost of acquiring them is offset by the saved cost of paying someone else to do the job......and you have the tools for future use!

Adjusting control arms, or adding control arm geo brackets is a simple bolt on task. The most complex aspect of it would be using a torque wrench to ensure the bolts are torqued to spec. If you have adjustable arms, the only other hard part would be having a wrench big enough to tighten up the jam nuts.




***EDIT***
If it's the kit Rednroll pictured above, and you have full set of adjustable control arms, you just need to get them all adjusted properly to solve your issues. In the rear you'd still run in to what I highlighted earlier with the domino effect. In the front, just need to figure out what your caster is currently, then either lengthen or shorten the upper arms accordingly to decrease/increase the caster.

 

If it is that same kit, then it came with fixed lowers and adjustable uppers.

Adjusting uppers is where I have to step back listen and let the experts take over. I think you shorten the uppers to increase your caster? I'm unsure, but I know a little adjustment on the uppers tends to make a big difference.

 

I really don't get the bother putting fixed lowers in a kit like that. Why should they dictate to an owner where that axle should be located with a fixed arm. ugh. Every jeep is different. fully adjustable arms are really just the way to go in general. y, use the uppers to adjust caster up front if possible. You can do it with adjustable lowers as well if that is all you have, but ideally the lowers place the axle where you want it, and the uppers adjust the caster.