A quick google gave:
http://www.kikatek.com/product_info....oducts_id=2128
Whether kikatek are a trusty site or not????? never used them, not heard much.
Anyway, I'm using the MX620. Similar to the revolution, but without the thumb wheel. Uses the same scroll wheel, but you turn the freewheeling on and off with a switch underneath (I think you can switch between the 2 modes on the revolution by clicking the scroll wheel??)
The MX620 looks similar to the MX1000, but no charging cradle. Don't let that put you off - I put 2 new AA's in when new, and Logitech's software said they should last about a year. I don't think that was a massive exaggeration.
I got my MX620's from (wait for it....) PC world when they had them on special for £20. Liked the first one so I got one for work and for the missus. If you do get it, google for uber options. The logitech software is pretty flexible, letting you assign the buttons for different things in different programs. Uber options lets you set
any of the buttons to do exactly what you want