As luck would have it, the manufacturer of the rims I need is just up the freeway, literally 30 minutes away, so that will save me a couple hundred bucks on shipping. SADLY, the rims are not at all very cheap.
I ordered rims from the Auto Drag series, which apparently is screen accurate. Here's a link directly to their page:
Here's the specs of the ones I needed. They are not usually stocked, so they have to build them. 2 week turn around time. Note that these rims are specific to my car, and the tires I've already purchased. If you are building on a different donor, with different tires, these rims may not fit.
Bolt Pattern: 5 on 5
Rear Rims: 15 x 14w (4" 7/8 backspacing)*
Front Rims: 15 x 10w (3" 5/16 backspacing)
These are the rims that my buddy Tim in Canada is using on his build, and he is happy with them. I believe these were based on recommendations from the dude who build the shell, who has no doubt overseen numerous successful builds.
I guess this means I'm feeling pretty confident.
*Please note that I changed my order on the rear rims. After looking at some reference photos, and comparing some contradictory intel, I decided to make the backspacing a little higher so the wheels are recessed a tiny bit. I can ALWAYS buy pieces that can undo the backspacing, but I cannot add to the backspacing. A bit of a roll of the dice here, but hopefully things will work out. Worst case, I can recover.