Do you NEED wireless? I use an Avid PT keyboard(love the key labels) and it has extra USB ports on each side of the keyboard(perfect for connecting a mouse). I have no problems running that thru a 50' USB Extension
Check the distance claim on the package(many are only good for 6-10') is you really need to be wireless(the wireless package I used in the past induced a helluva noise into guitar and bass if I tried to play while sitting at the keyboard/mouse