Yeah do it right sleeves, gussets, and while it's all torn apart toss in 5.13 gears. You'll save on labor if you find a good shop who can do it all.
You can always drive with it with the 35's and see how bad of a dog it is, and if you it's worth the extra grand beefing up the axles. I ran with 35's for 6 months on 35's (I have an auto rubi with 4.10's) and it wasn't too bad, but hills were causing constant sporadic shifting.
As far as finding tires a couple of tips:
Go to the manufacturers website to find sizes made (check tire weight, load rating, etc to see what fits your needs)
Go to the store website to see if they sell that brand
Order them thru the store that carries them...they rarely stock large tires.
RUBI / 37" Grappler's / 3.5 RK X / 5.38's
RockKrawler : PoisonSpyder : RCV :LOD : Iggee : sPOD : Nitto : WARN : Yukon : Rock Hard : Tatton : PolyPerformance