Honestly, I think you should just poke around, see what looks nice, and give it a shot for now. There's so many different caps and profiles and materials that you might end up with something you hate or something you love.
Some people love PBT caps, some swear by doubleshot ABS. Some drool over SA profile while others can't stand typing on 'em.
Asking what keycaps you should get is just such a broad question. You're going to wind up with answers all over the place.