My car (BN6) had TR6 seats in it when I bought it. I hated them! If you aren't too tall, you could get away with having them in there, and yes they provide better support/comfort. For me they completely ruined the look of the car as the headrests stuck up above the body, not to mention the fact that it made it a real squeeze to get in the thing. So yes it can be done, but any seats with headrests would in my opinion not be worth it.
I went and bought a new set of original style seats and put up with the lesser comfort.