You'd actually be better off just designing in a pocket to put the mouse then whomever buys your project in the future (if it works out) won't have to buy a customized mouse - they could use any mouse they wanted. You have to remember that not everyone uses an Apple mouse with a Mac.
Also think about this - to not intefere with the gliding motion of the mouse you're going to have to have the magnet flush with the bottom of the mouse or even slightly recessed so when it glides it doesn't hang up on the mousing surface.
Successful industrial design isn't easy - lots of things to think about instead of the immediately obvious. Concepts are good, but you have to put yourself in the mind of the end user as well. Idiot proof as best as you can.