G6 is a good choice but really expensive.
If youre gonna get one, get a chinese one on dealextreme for $45 (out of stock now)
If i was gonna reccomend anything it would be either the EZ4 Deluxe(which is damn near perfect, just no RTC and that only affect pokemon)
Or the EZ 3in1, which is better than actually advertised since there is a homebrew program available that allows you to play gba games from the PSram rather than the tedious burning to NOR as they would have you believe.
G6 also has a few glitches/slowdowns apparently with some games(it says so in the review on dealextreme) and EZ4 is perfect for GBA. As for pokemon, you can patch it so the time goes forward while youre playing. It will only affect collecting berries since they take a day to grow.