Enjoying my rg353vs, very handy for lounging playing something without really feeling like you are committing to getting too "settled in" to a gaming session, easy to pick up and put down
Get a decent SD card, use internet archive to get some rom sets (the set below is a good start for PS1 and older).
Archive.org/details/tiny-best-set-go
I also used a program called chdman to do some conversion of the compressed ROM files for some systems, probably some of the other roms I had downloaded to fill in some gaps in the sets iirc