The most important thing to look for (imo) is programmability. You want a board that supports QMK or ZMK firmware. This lets you set up stuff like mod-tap, macros, mouse keys, etc. Mod tap is my favorite thing ergonomics-wise: v and m act as shift when held, normal letters when tapped. Really takes the strain off my pinkies. I also like having a navigation layer: hjkl in this layer act like vim-layout arrow keys.
I use a ZSA Moonlander. Best investment ever.