Single or Twin turbo setup for 360?

I think the only part of an eBay "kit" I'd bother with is the plumbing but that's just me. I'd also definitely go with a different cam, MP cams are pretty obsolete and "RV" cams don't give much better performance than stock. Not that it wouldn't work it's just there are plenty of better options out there. Although if it was my build I'd be looking at getting a junkyard 5.9L Magnum or roller-cam LA 360 for the factory roller lifter setup as I don't trust flat-tappet stuff much these days. If it had EFI the cylinders are likely in good shape too and won't require machining. According to Magnum Swap -your source for Mopar engine swap information. a 5.2/5.9L can safely handle 15 psi on a stock bottom end.

Also there's a sub-forum here called "Forced Induction Mopar" you might pick up some info browsing through there if you haven't already.