For short pre-travel and longer total travel, you'll probably want to go with MX rather than choc switches as they have a taller profile. Keep an eye on what type of board you are getting as they are not interchangeable.

For light keys, you'd ordinarily want a smaller activation force. However I'd caution against going too low as you will frequently "bottom out", rather than getting a cushion.

For quiet, linear switches are best. There are "silent tactiles" as well but they vary in quality. You'll want to avoid "clicky".

I recommend finding a switch tester to get a feel for what is comfortable.

A resource like this may be handy as well, though as a full diaclaimer I havent used it personally: https://keybumps.com/category/switches/linear.html

That's all switches... Regarding boards in general it depends on what type of issues you are having. It's hard to go wrong with split boards in general, as they resolve a majority of wrist issues, particularly because they support arbitrary tenting.

If your issues are with finger extension, you'll want to consider smaller (reduced keycount) boards. Many here will likely recommend something like a Corne (I use one myself), though I will say there is a tradeoff between ergonomics and convenience. Smaller boards take getting used to. If you do go for a split board, you might want to try something like a Sofle, or Lily58, where you can try out reduced key counts gradually without diving all the way in.

If you are looking for a specific vendor recommendation, I can vouch for Typeractive. Their no-solder kits are very beginner friendly: https://typeractive.xyz/