A board member mentioned last year that he was using a Flow Kooler (part# BRA-1621...$78.96) & it was working very well.
Now, with that said, I have done a little research on TR boards about this very subject. It seems that 95% of the TR owners who chimed in were either using a stock replacement or similiar. Most of them suggested replacements from the local Autozone, Pep Boys, you name it. I guess higher flowing w/pumps aren't widely used from what I've seen/heard.
I bought a Carter? pump from Poston's right after I bought my TR. It supposedly flows a bit more than the stocker. I have yet to put it on, but I plan on using it on the new motor once I get it in the car. Hopefully it will work ok. HTH