Great to see your interest in the RX-7, it is a brilliant car.
If you want handling, you will have it with the RX-7 - it is still years ahead of many other sports cars produced today with its suspension technology. Better still you will also have LOTS of power on tap!
If you were to take one for a test drive now, you would probably want to end the contract on your mini very quickly
In 2 years time the RX-8 will be out also, which would be worth considering - but of course the RX-7 will be much cheaper then as well.
As for purchasing one, same rules apply to that of purchasing a used piston engined car. It is also a good idea however to find one that is completely standard, as the tuning on the turbo rotary is very specialised and it has to be done right.
There are some other threads in this section of the Forum which will probably answer more of your questions - but if not, just post another one in here!