'70 Dart 392 Project; what direction?

Got a little bit of a decision to make on the rearend... I've got an 8 3/4 housing here and a 741 case/open with 3:23 gears. Pricing everything out on Doctor Diff's website and I think I'm around $1600 for axles/rebuild kits/bearings/suregrip/brake kit...etc I've emailed Cass a few times, but they're closed for the next week. When I asked for advice on rebuilding my centersection he just sent me the 489 Modular Iron case he offers.

That got me thinking. Just last night I've found 2 different Dana60 truck rearends. One is a Powerlok with 3:54 gears/drum brakes. Older 5x5.5 Bolt pattern.
The other is a newer 2000 Ram 2500 axle with disc brake setup. Gearset unknown, seller says it was recently rebuilt but someone did it wrong so it needs a new gear set and claims it is a limited slip as well.

Both sellers claim they're true D60's and not the D61 or D60HD. So hopefully we'd be good to go there.

Since the work for narrowing the 8 3/4 and the Dana 60 is the same, I'm leaning towards a D60 swap. The drum brake D60 I can buy for $500 (doesn't need gears) and the Disc brake D60 I can buy for $350 (needs gears but has discs already). I'm unsure if I can reuse the calipers and mounting hardware on the Disc brake housing if I narrow and buy 5x4.5 rotors.

Any advice would be appreciated! :)