You’re just looking for a perfectly ordinary Windows keyboard. I’d happily recommend a Logitech K120 keyboard - it’s USB, it has the little folding legs to adjust the angle. It has no extra USB ports, batteries, wireless, bluetooth or other bells and whistles.
I think I bought this one because at the time it was the cheapest one on Amazon (it was about £10, and seems to be about $10 for the US model in the US - I don’t know what country you’re in). The only other deciding factor for me was that it has deeper key travel than some of the slim-profile keyboards that laptops now favour. That just comes down to personal preference.
I’m on this journey as well. I found that TKL is nicest to stickerbombs in general, but eh … You need smaller ones.
I believe the way to go is to build one, cuz then you also get to sticker the plate. Most boards that are off-the-self have a very uh … Rocky case, so tad bit more difficult to sticker-also bomb the back. If you want an underglow, I 'd say use a DZ60 PCB. Encourages MX.
I didn’t find a cheap 60 percent case with a nice sticker bomb bezel, although I do know that some wooden cases at falba.tech have a little bezel. Otherwise, a standard plastic cost-effectiveness case
I have this one from KB Covers - it’s a keyboard with imprinted key caps.The keyboard is nothing to write home about, except it’s better than the Apple ‘magic’ keyboard which is terrible. Very useful to have the caps there while I learn.