wheel and tire fittmen ? help!. Ive searched

I have a 67 cuda F/B. I'm looking to put a set of 17" centerlines on it. Now, I am installing the SSBC front disc kit which has provisions for the 5x4 and 5x4.5 pattern. So, obviously I would want to want to go with the 5x4.5 pattern and I guess I will need to get spacers made for the back?. Yes or no?. Also, if I want to "stagger" the wheel and tire sizes, please give me your expertise on what is the "best bet" size wise on both the front and back so there are no rubbing issues?. I am looking at getting a 17x7 in the front and 17x8 in the back IF this is doable? Can anybody help me for sure?