Since most USB keyboards and mice are made for Windows systems in the first place, and most have drivers for Mac, it shouldn't be too difficult. As someone here said, the Apple keyboard works with Windows, and I know I've used the Logitech MouseMan Wheel on both PC and Mac. It's a good mouse anyway, so might be worth a look.
Tho' I'm sure that fancy new MS Intellimouse Explorer would work splendidly as well, and since you're already tainting your household with MS products, it's gotten good reviews.