One extra note: take a closer look at the drive you choose, and ensure that it does have some onboard RAM cache. The lowest end Crucial ones might lack that, and for 20 quid more there'll be a very similar model which does have some RAM cache.

You WANT/NEED some RAM cache on the drives, otherwise writes can be painfully slow and endurance will suffer.

EDIT: Ah. Yes, the MX500 is the one to buy. They also have the BX500 which is the stripped-down version: avoid for server or main machine uses.