I switched from 16.5 split rim to stock 16" 8 bolt wheels I got from pick and pull. I paid about $25/wheel, and then bought tires to match. However, these are stock width rims (8"?).
If you have a high GVW C-20 (my K25 is 8200 lbs GVW) you need to use 10 ply/E load rating tires to maintain the cargo capacity. They are a little more than standard truck tires, but still easy to find. Stock height tires are usually 245/75R-16E - about 31" tall.
Bruce