I think the website I gave, I am not sure what country it is in. I think I paid around $50 US for my smart cat touch pad, and there is a cheaper one also. Your cheapest option would be a trackball, for around $20, you can look at these at pretty much any electronics store. Any software option is going to be more expensive. For voice recognition software, like Kingdom said, Dragon Naturally Speaking, it is the best, its around $150 (and thats cheap for assistive software, the program I am using to type this cost $300). I use a Logitech Nulooq Navigator as my switch/controler, pretty much I use it to scroll up/down back and forth on pages, but I have it programed to do different things for each program I use, it cost $70.
Todd