'70 Dart 392 Project; what direction?

Moving towards the rear of the car I'm starting to research my 8 3/4 build and tire plans. Widest tire I can fit on my planned rear wheels is a 305/45/R17. Puts it at 12" wide tire.... My wheel wells are measuring about 12.25". So the minitub may not be needed. What I do know is that I'm going to be narrowing my axle housing and converting to rear discs, and will for sure need a leaf spring relocate kit.

Does anyone have any recommendation on a rear disc kit? Since I"ll be narrowing my housing anyways I might get by with a less complicated kit rather than adapt the old drum brake flanges to disc brake?

Any direction or tips here would be greatly appreciated! I think it's smart for me to get my drivetrain buttoned up before I move onto wiring/efi/fuel system....etc

Mike @ HCA