Wheels and tires, I cant really help on as Im not at that point yet as far as what will and wont work. Tire sizes you posted are 225(width in mm) 60 is the % of the tire height vs width(profile) and 15 is tire height. Hope this helps
215/60-15 is ~ 8.7" wide and ~ 25.2" tall.
225/60-15 is ~ 9" wide and ~ 25.6" tall.
I say approximate because each MFG is a little different and section width can vary with wheel width. Either tire will fit fine on a 7" wheel. What exact offset or backspace you need will depend on which spindle and brake package you are running. A 15x7 wheel with 4.5 backspacing would fit on the front of my car. Deeper backspace requires a larger diameter wheel. A 17x8 with 5.5 fits on my car with a 245/45-17 tire. I have '73-'76 A-body spindle with the '78 Cordoba brake rotor. Rear backspacing will depend on the axle you are using. Mine was custom made, so nothing I have done would apply to your case. Currently I have a 325/50-15 on a 15x10 with 6.5 backspacing under the car. This requires significant modifications.