Blank Scrabble tiles?

Hi all,

I'm trying to create a crude prototype of my board game design and need some help on finding the relevant components.

I need to get hold of some square plastic tiles similar in size and shape to Scrabble tiles. Preferably I'd like them to be blank so that I can place stickers on them.

The playing board itself will be grid-like onto which the plastic tiles are placed but ideally just like the Deluxe version of scrabble I need something that keeps the tiles in place to stop them sliding around.

There seems to be a lot of component manufacturers out there and before I attempt to make these items myself I wondered whether anybody may know of a supplier who can produce these types of components.

Any suggestions most appreciated,

Regards
Dud