71 c10 offset

[bagged ls1]

Hey guys, this is my first post after many hours browsing over time. I have a 71 c-10 lwb I have been collecting parts for and Im stumped on the wheels. So far the truck needs body work and paint and so far I'm still in the buying stage. Have a 01 corvette ls1 with custom ground cam dual valve springs titanium retainers, 2600 pound air bags with 8 inch c-notch, 3 inch drop spindles with 1 inch bag cups. 4 1/2 inch valves, engine driven air compressor, billet grill with new polished grill shell. Almost done buying parts and now Im looking at the wheels. I really want to run a 22 out back and 20 up front or 22s all the way around. I cant seem to find the offset thats best. Its a 5 lug bolt pattern and the last thing I want to do is spend 1500 on rims and they not tuck inside the fender wells making them useless for a bagged setup. If I have too Ill even run a 22x8.5 all around. Basically everytime I call a rim shop, there useless.. Help please