Does anyone know how thick factory coil spring isolaters are, i want to replace them and get .5in of lift. So what isolaters/spacers would give me .5" without the factory isolaters

0.685"

^ thats how thick the factory isolators are, so you would need to replace them with a spacer/isolater that is 1.185" thick, and then you would end up with a .5" lift

Just buy a 1.5 inch spacer and youll be set.

If I put a 3/4 inch lift kit will I have to do any additional work? If I put on a 1.5 inch lift kit can I leave everything else standard?

You'll be fine either way. Here ya go:
http://www.seriousoffroadproducts.co...G-SPACERS-1.75