Wheel Fitment Advice Please

Hey guys, need some help here.

I was sorting out a rear end noise this past weekend when I noticed that my one rear rim is warped :/ They were a vintage set of wheels so it's going to be a pain to try and find another wheel from a company that went under a long time ago.

That being said, I'm using this as the opportunity to get into some new wheels!

I have a 68 valiant signet. I swapped out the 7.25 for a 8.25 out of a duster to go up to the big bolt pattern. The wheels I'm looking at for the rear are 15x8 with 4.5" backspacing, I plan on using 225 60R15 tires on these, will these fit without issue? Or what would be the ideal backspacing?

Second question is regarding the front. I plan on using 15x7 with 4.5" backspacing with 205 60R15 for the front. My problem is that until I can afford a disc brake conversion, tubular control arms etc to upgrade to the BBP, I'll need to use wheel adapters. Will these fit? Any help is appreciated.