@kelbot can't say I've tried playing video on it; my phone kinda already fulfills that purpose for me. :)
Tbh, I don't have much experience with various loaders and flashcarts. I got the #Acekard2i #flashcart years ago since that one was at the time one that was well-developed, supported and quite cheap. It's still running (a rather old version of) #AceKard All In One (#AKAIO) because it seemed to be the most popular and actively developed loader.
https://wiki.gbatemp.net/wiki/AKAIO
http://www.akaio.net