Mato's brilliant. If you haven't seen his Legends of Localization website, where he discusses various issues related to translation, and even does simultaneous playthroughs of games with different translations (including machine translation!) and compares and contrasts them with the original...you're in for a treat.
The Mother 3 English translation is unbelievably good, it kinda makes Mother 2's localization look like a hack job by comparison. Now I've almost got a reason to go back and give FFVI another pass...
You'll need a copy of the rom to patch. Also I'm pretty sure you can play it on an actual GBA if you have a flash cart. If you play it on an emulator make sure frame skipping is off because the rhythm aspect of combat is almost impossible otherwise.
