I went to BBP with my 71 dart grabbing everything including and bolted to the upper and lower control arms from a 73 dart (didnt need the lowers but they were included). Disk brake cars used a larger upper ball joint so you'll need that. I think I paid around $325 for the whole set up and included the prop valve from the donor car. On the rear I ordered a set of axles from Mancini Racing (Yukons) with the 3 inch studs and green bearings installed. What kind of ideas are you kicking around?
There are numerous ways, I believe you can buy adapter plates to go from 5x4 to 5x4.5, but I'm not sure how safe they are. But for the front wheels you will need to switch to big bolt discs (73 - 76 A body), and for the rear wheels you can either buy a set of big bolt pattern axles, or switch to a big bolt 8 1/4. Someone correct me if I'm wrong.
what i was thinking about doing was leaving the small bolt patter up front on my car and swapping a different rearend- 9 inch, but i would run steelies with dog dishes