A regular Mustang T5 set up will bolt right up to it, bellhousing, transmission, clutch, flyhwheel and all. (just need to make sure you have the right flywheel imbalance, 50 oz or 28 oz, can't remember which. The crossmember should be able to be modified to work without a whole lot of effort. The original driveshaft will work just fine. Really the only "difficult" part will be rounding up the clutch assembly which shouldnt be that much trouble. You'll have to get a little creative with the shifter as well but no big deal.

A note on the T5. It's a big truck, fairly heavy with a engine that makes pretty good power. The T5 won't take much abuse from it. I would recommend a Tremec is your going to do it right.

I did this swap, with a Tremec, in a '94 Econoline van about 12 years ago. It was pretty cool!