If you have to have the AT, it makes sense to go with a V6 of some sort, or even a small block Ford V8. The tunnel and firewall modifications you'd have to make pretty much dictate an AT because you'd not have enough room left for three pedals. If it weren't for the AT, or for the sake of just proving that I could do it, however, I'd be dubious about such a complicated and expensive swap. Some modest modifications to a B20 plus a bit of suspension and exhaust upgrading will get you pretty close to the kind of performance you are after. Another $2-3k will put you into territory where, unless you are going to race the thing, you'll hardly ever dare to test its full capability. My two cents' worth, but then, I am a bit of a stodgy, old fogy.
Bob S.