GameYob is an open-source gameboy emulator for the DS. It has excellent compatibility and speed, and runs many games flawlessly. Notably, it can use the Gameboy Color bios to colorize pre-color games, just like on a real gameboy.
I went to auction at a mom/pops video game store few months ago that was closing, and bought 11 slims for $200, 1 was DOA but 10 work fine. so hella deal. Already rgh3'ed 8 of them. But most younger kids don't even want anymore, unless it plays stupid "fortnight", or newer shit.
Ah, yes, portrait mode, surely the best way to film a row of people. If only there were some way to fit a wider shot, at the expense of height... if only...