I have a Microsoft Sidewinder X4 keyboard and a Logitech M570 trackball.
The keyboard is very nice to use without too many dohickies that I don't use. Illuminated and has a nice key action for a membrane keyboard with full n-key rollover. Very easy to disassemble and clean out cat yak it turns out. Works well for games and typing alike.
The M570 is comfortable enough. I can't use normal mice these days (my wrist just locks up in a few minutes) after around 20 years of trackball use. I still prefer the shape of the much older TrackMan Marble+ design as it was a lot flatter. The biggest negative for these is they seem to last about 10 months and then one of the micro-switches will fail. I've had 5 or 6 now (mostly through warranty). When my current one dies next year I'm not sure what to replace it with as the options are very limited. It's a shame as for a £50 product there is plenty of room for improvements.
I am a gamer (although not so much with kb+m games these days) and never felt the need to splash out on the expensive toys in this department. I used to play BFV on an old cheapy MS keyboard and my trackball pretty well way back when.