Allow me to suggest a Ford 5.0L/T5 in a Mazda RX7. RX7s handle great, and don't look bad, but the rotary is often too much trouble.
If you get a 5.0L, there is a massive aftermarket, for as much power as you want. Even a 250hp 5.0 will make a 2300lb RX7 scream. The RX7 was designed by Mazda, at about the same time they designed the Fox platform. If you put the engine/suspension crossmember in backwards, a Ford smallblock with Ford mounts will bolt directly into it, and a 5.0 HO will even fit under the hood.
The modifications required are a new tranny crossmember, and a custom length driveshaft. Both are relatively easy to do, but you can also buy them from Granny's speed shop. There are lots of people who have done this, and it is very well documented.
If you have something against Fords, you can do the same thing with a Chevy or Dodge engine, but you will need a custom front crossmember... $$$
http://members.tripod.com/~grannys/