I’ve had smaller, higher-strung cars. The Miata is a great choice. It’s easy to overlook the work that went into it’s design. I could recommend you buy a miata, then spend your money on learning to DRIVE it. You’d be rewarded with a car that’s as quick as cars with twice the HP, and a much better idea of what a car can do around a track.
I’ve had an 87 Turbo RX-7, I’ve also had a 4 banger PT cruiser and now drive a Subaru STi.
My thoughts: The RX-7 was pretty far gone. The turbo bearings were going, there were a ton of vacuum leaks. But. An engine swap would be pretty easy, and returning it to stock performance with a new turbo and vacuum hoses would be a pretty good lesson. Further, a non-turbo '7, with new plugs, runs GREAT. But you won’t hit the 12’s with it, it’s just too old a car.
The Cruiser was fun in a driving a slow car fast kind of way. But it had no sporting pretensions whatsoever, and got BORING after awhile.
The Subaru is a real hoot. Dead nuts reliable and FAST. but do you want a car you just get in and drive? I bought it from a kid that riced it a little. Shaved all the emblems, swapped out the interior, put lowered springs on it. First thing I did was restore it to normal ride height. I hated the ‘bobblehead syndrome’. I like that it’s got the WRX spoiler and that it doesn’t advertise.
Your ultimate performance will be limited by your foundation. If you start with a strong sports car, you will spend more time MAKING power and less time finding the next weakest link.
Lastly, a high strung 4 cylinder (or wankel, for that matter) CAN make power, but at the expense of day to day drivability. HP is for bragging rights, but torque is for driving. Do you wanna brag, or drive?