If still needed, I’d suggest sticking to 8 MB ones and dumping / restoring saves through uLaunch Elf and a a USB stick. (or similar solutions for moving to / from more standard storages)

For handhelds, I have a Supaboy, a PSP, a PS Vita, a 3DS old, a New 3DS XL and a Switch.
Out of those, the Switch is the only one I can’t play emulated games or homebrews, given I haven’t modded it nor there is flashcarts for it.
And among the ones we both have, the 3DS XL models seem like the best ones. Not very heavy while still being decently sized, good resolution and color palette, buttons with good pressure, and for emulating Nintendo games, Nintendo’s own devices are usually the best for their given release period.

Mint 21.1 Xfce, and if Android counts, ArrowOS 13 (on phone) and BlissOS (on an old computer)