i prefer to play my runs on a model agb-001, as it's what im used to and its the only of my gbas that have fully working L/R buttons. what would be the best way to record this?

I wish I knew... As far as I know there is no capture card made specifically for the GBA, be it the original or SP model, so... :|

new discovery: i can hook my camcorder up to OBS so i can record with splits. theres a slight problem, though, it won’t record sound. is this ok? or do i need sound?

I dont see it being a problem. You dont even need video since its so awful trying to live record this game on original hardware. Don't worry about it too much

Gameboy Player could be an option if it didn't cost $100 for just the disc...

There are GBA-to-TV cables that would let you play on the GBA screen and record with capture card on TV, but it only works on original GBA, and must be soldered to the motherboard for a stable connection. I have one, just haven’t finished soldering yet because I want a backlit GBA screen first