Nicely done on the build plan sheet. Years from now you'll love being able to look back at that page and have it all referenced right in one post.
Re: wheels. I'm a HUGE proponent of the "stock appearance but wider and in manageable size" plan. Try Stockton Wheel. They will build you a set of wheels according to your specs. The series 20's look like they'll do the trick.
http://www.stocktonwheel.com/heavy_duty.html
Going 16x8 will make a world of difference in tire selection. 15's are ok for hot rod tires, but lousy in all terrains and E load range tires.
I would spend the extra dough to get the right wheel. A solid set of rolling stock can make ALL the difference in your ride's appearance. 16x8's with caps. and a cool set of white letter all terrains, a nice level/lift and you're in business!
Check out Stockton wheel, or even give Wheel Vintiques a call, I'd bet they would build you a set if you asked.
Engine wise, check out Blueprint for crate motors. A buddy of mine just picked up their 365hp 350 and put it in his 70 C10. Has nothing but good things to say. Pretty hard to beat, fully dressed minus headers, 50K mile 30 month warranty for 4k... and it'll bolt right up.
https://blueprintengines.com/product...tor-bp3501ctc1
Keep up the good work, you'll get that rust patched up soon, and be on the road before you know it. BTW that pic of your daughter behind the wheel is priceless! I'd frame that one!