If youre looking at have a 600hp+ daily driver the rotary probably isnt your best choice.
Why choose a number like 700 anyway?? Horsepower is just a number although a very important one. Still it doesnt decide who wins or loses a race. What good is 700hp if you never have traction? Or you break something new every other run? Or if the driver doesnt know how to control it?
Most import mags (and websites) tend to make even the craziests swaps look like changing the engine on a Lego truck. There is a LOT of planning research and cash that flows into those projects. Not to mention time. They dont tell you what they had to go through for motor mounts hood clearance problems moving the steering rack if they had to cutting the firewall fabricating custom parts and on and on...
Not trying to discourage you just wanted to let you know whats lurking around the next bend..
-j0lt