I think 35's on scout 80/800 width axles would make for a very compromised turning radius. these truck have uncommonly wide frames, you'll end up with the tire rubbing the springs/frame with not much steering angle.
Scout II Dana 44's are ~2" wider than stock Scout 800, and are somewhat available. I couldn't find one when I went looking, so I narrowed a Blazer Dana 44 to use Scout inner axle shafts. You'll have to relocate spring perches in either case, I think - Scout II's had narrower frames.
There are lots of parts on these trucks, especially in the suspension/steering/brakes that I feel are really outdated and benefit from upgrade to something more modern, but it all depends on how much of a project you're looking for. I'm basically just keeping the Body and Frame, see link in my signature if you want.
I went with a Chevy 350 V8 with TBI, but a 4.3 V6 would be a solid choice too. If I were collecting parts right now I'd go with a LS series engine, probably the 5.3 out of a truck.