Rims and tires question. Help!

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Hello everyone my name is Jim and I'm new to this forum (lurking for awhile). I've recently bought a '71 Chevy Chevy C10 lwb that's all original including the rust. Tires and rims are the first things I'll be installing and after shopping around I've come up with many questions. I'll number these questions so if any one can answer any please help me out. Chrome smoothies are what I want
1. Quality - Hard to find now a days. If I could buy the most expensive to assure quality that's what I would do, but? Cragar, American Racing or LMC's unnamed brand in the catalog? Any pro's con's or other suggestions where to buy.
2. I now have the stock rally wheels (5 bolt). What is the stock width?
15 x 7?
3. My stock wheels have P235/75R15 tires. Would this tire size work with 15x8 smoothies?
4. Rim offset and backspacing??? If my rims and tires are wider than stock what do I need to keep the center same as stock?
5. Is there any limit to how many stupid questions I can ask?
Thanks in advance for your help!
Jim