Xr4Ti
Rare Euro inspired. tons of parts available for 2.3 Ford, and I'm sure they're a lot cheaper than the Rotary.
ALSO, Western motorsports knows the 2.3 Turbo motor quite well and can hook you up. Might be tough getting rotary specific Parts and service locally.
EDIT: If you're serious about the Xr4ti, Why not look into the Mustang SVO? those cars Rock!
"The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents... some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new Dark Age."
-H.P. Lovecraft