For starters, yeah, avoid PAL like the plague. Secondly, these days you can buy an entire Japanese system for the price of a converter, so, IMO, they are a huge waste of money.
If you plan on eventually getting into CDROM2 (you will want to , whether you will want to pay for it is another matter) you are going to really wish you didn't buy a TG-16 in the first place at all since the CDROM unit for it is comparatively rare unreliable.
Best choices, in the long run:
A Duo R, switched
or
A Duo R and a TG-16 to play US HuCards.
These choices have a higher initial investment cost, but in the end will be more reliable and fun. A modded Duo R with an Arcade Card Duo will play every TG-16/PCE game released, world-wide, except for the SGX games (which are OK, but not that awesome) and Altered Beast (which is utter shit). When you have a setup like this you can stop "collecting" and focus on playing.