I don't know the best place to buy them, but so far Ive been reasonably happy with the Andy-Crimp Pro, and the connectors I've gotten from
Quicksilver Radio. The other crimper people seem to like, it the TRICrimp, which is available from
Power Werx (and maybe some other places, too).
I've ordered from both places. Quicksilver is quite slow with their processing, and the service from Power Werx was very good.
I converted to crimping a while back, and like it. I just made up a short coax jumper cable yesterday, and was glad to be crimping, and not soldering. I DO still solder the center lead of the coax, though (relatively easy).