Supercoupe's can take more money to maintain, but any car has that capability, the SC just seems to have a history of it.
As far as dumping an Explorer motor in w/ a forged setup to handle the boost of a blower, no problem. All you really need is the money to do it. And as far as the "Mustang" 4R, it doesn't matter. You can build any 4R to handle power. I would talk to Darrin about that. And have Alan build a TC for it.
If you plan on going w/ this combo, have you given thought to the extra cost of upgrading the rest of the drivetrain, rearend, etc.. Also a chip/tune to make it all work.
If this is going to be your DD, then I wouldn't plan on driving it for a while as these mods don't always come quickly, unless you have a bunch of cash laying around and can pay someone to do it all. Just speaking from experience, since it seems that once you start a project, about 12 other things crop up that you have to fix or buy along the way just to make the actual mod itself happen.
Sounds like it would be a good plan if you go that route though. More power to ya!