Yes, Jegs.com has everything you need. Anthony Jones K-member, motor mounts, trans crossmember, and headers. The full kit with headers is roughly 1,000 bucks.
nothing
yes
Is it possible? Yes. Is it worth the effort? Not to me. That takes a lot of effort and expense.
I know you can fit 187 in the horse, I'm not sure about the car though...
You Can Put a 1988 Transmission In a 1993 Mustang Body.