I have had a Logitech BT mouse for almost 3 years now and its awesome! I don't notice any lag or issues. Plus u do not need a USB receiver, BT works like a charm
V270 Cordless Optical Notebook Mouse for Bluetooth
http://www.giantmike.com/reviews/LogitechV270.html
System Requirements:
* Mac OS X 10.2.8 or later
* Bluetooth enabled computer (built in or via adapter)
Is Apple selling wireless keyboards with numpad?
I only find these with USB connection (cord)