Lifts of under 4" won't "require" driveshafts. 4" they're recommended by many kit manufacturers. 5"+ they're pretty much required.
At 3.5", I'll tell you what I'm doing (I'm going Rock Krawler, but same idea)- front track bar, rear TB eventually, front lower control arms (to correct caster), rear upper control arms (to correct pinion angle), and that's about it. Keep it simple, and save $ for when stuff breaks