Welcome to GH!
Like everyone else said staff away from the classifieds otherwise your wallet will hate you. As for the white keycaps get PBT, they are more expensive but last longer than ABS.
burr... ah... welll... remember the PBT white blank caps they're selling are usually KBC made, which means they're not a PURE white, it's a BLUE/VIOLET shifted white...
A more neutral day-light white, can be had from WASD keyboards, they are however ABS, but that's fine since bright colors offset shine.