Wireless Keyboard / Mouse HELP!!!!!

Spent wayyy too long looking at these now and need to make some kind of decision. I have altered my computer set up so my poker computer is upstairs with my work computer. Before I had 2 seperate set ups, one in the living and one in the office, and now I have both computers in the office sharing a dual screen (they will never be on at the same time so it doesn't matter).

I want to get it so that I only have one mouse and keyboard so operate both of them. For my gaming comp I have wired mouse and keyboad (Cyborg Rat 5 mouse and V7 keyboard) and for my work comp I have a standard Microsoft wireless keyboard and mouse. In the short term I'm happy to switch the dongle for the standard wireless mouse / keyboard between the two but I would like to upgrade them so I can have a bigger mouse.

The one with this is relatively small and I'm going to be using for 12+ hours a day sometimes, so I dont mind spending the money. The main thing is that I can use the set up for both computers without having to switch dongles over, but I'm not sure if this is possible? It really annoys me because I've been the Currys / PC World and they dont have any of the high spec stuff out on display (or in Scunthotpe in stock) and ideally I would like to try them out first (but if something comes highly recommened than I would just order it).

Cliffs: Need one decent wiresless keyboard / mouse setup (for user with large hands) to operate two computers (not at the same time).

Thanks in advance.