Shouldnt be any interferance but you may have to deal with two receivers.
If you can get the radio signal mice. Dont need line of sight with receiver.
Dont know if they make a keyboard that uses radio waves.
Microsoft's wireless keyboards and mice and pretty interchangeable (assuming you buy them at roughly the same time and not 3 years apart). I suspect the same is true with Logitech.
The problem is that most wireless keyboards are not sold seperately. They are usually sold as a bundle with the mouse. Its definately not good when you find a keyboard you like in one bundle and a mouse you like in another.