Definitely R4. TTs have way more errors and R4s have more ROM compatibility. But there are many other types of Flash Cards, such
as CycloDS, AceKard, and EZ Flash V, just to name a few. Go on GbaTemp and they have reviews for heaps of different ones. Then, just
search one online and you may be able to buy one off Kick Gaming or Game Yeeeah or something...
<breaths>
lol