He definitely doesn't need a 4 rotor or even a 3 rotor. In fact, there is one guy on the Rx7club who has done a 10.98 on stock twins (just over 400 rwhp). Believe me, that is an amazing feat, and I doubt it will be duplicated. To run 10s in an FD you'll want around 450 rwhp or more. That could easily be done with a big streetport and decent-sized single turbo. Of course, you'll need the fuel and ECU to control it. I would just use the stock wheels and put the new MT Drag Radials on there. You'll want to beef up the rear end with a 86-88 Turbo II differential (and eventually the axles as those won't last forever with 10 second passes). Beyond that, set up your ECU (Microtech has this feature) with a rev limiter to build boost at a stop and learn how to cut 1.8 or better 60' times and you'll be well on your way to the 10s. Of course, I didn't list every other mod like a FMIC and a clutch, but I think you get the idea.

On another note, you could put a mildly cammed LS1 in the car making just over 400 rwhp and also run 10s. That would be a hell of a lot cheaper if you're mechanically inclined, and it would also be reliable as hell.

Please spare me the bleeding heart rotary comments about taking out the FD's soul. An LS1 does NOT negatively affect the weight distribution either.