Multiple Wireless Mice/keyboards

Since the director is keen on "state of the art" appearance in the new facility I have been considering a fully wireless system. This includes the mouse and keyboards for the notebooks (desktop replacements). The notebook keyboard and screen are fine for travel but not for 8 hours a day office usage, would be a strain on the staff - spreadsheets, word docs, database, etc, thus external keyboard/mouse.

Most wireless mice/keyboards operate on RF(non-bluetooth) and RF(Bluetooth). In both cases the majority use 2.4GHz frequency which is the same as the 802.11g WiFi transceiver (the notebooks will be using WiFi for connectivity in the office). The question is how much of an issue will interference be, specifically with the WiFi and also cross links between one desktop mouse/keyboard set and another one. Don't want secretary 1 controlling secretary 2's computer.

I realize most allow pairing between receiver and mouse/keyboard but not sure how effective it is. So, if any members have experience with this type of setup please advise.

P.S. I have seen some operating at 27MHz so this would then only be an issue with mouse to mouse interference. Desk to desk distance could be as low as 2 meters.

P.S.2 Also specific recommendation for mouse/keyboard. I personally prefer Logitech but find Genius to be reasonable.