A better radiator would be a waste of money. The current bathhurst model is running far more HP on the same rad. The rad is more than adequate.
I love the things but they are unreliable.
I can afford to buy one, but cannot afford to fix it, and I do all my own wrenching.
So I stick to the cheapo first gen.
A T2 may be the best Rx-7 deal out there. For less than $5k you can have a 13 sec very nimble car that’s reliable and tame enough for a daily driver.
Jusy my $.02