I have used wireless keyboard & mouse combo units and found that they are totally unreliable. The thumb stick is nearly useless in precision and doesn't allow you to quickly move the mouse around the screen. They also tend to run through batteries quickly, and when running low on batteries they will miss key presses or mouse input randomly. I searched for a wired keyboard & mouse combo and found that my options were very limited. Many of them were built for media center PCs and have non-standard keyboard layouts, small keys, and were also pretty expensive.
After running out of other options, I decided to roll my own! This instructable will show you how to take an ordinary USB keyboard and USB trackball mouse and combine them into a single unit. The units in this instructable are WIRED, however you should be able to do the same thing with a wireless keyboard and mouse, albeit at a much higher price.
Step 1: Gather the materials...
1) LITE-ON Black USB keyboard - $7
2) Logitech Gray 3 Buttons + Wheel USB TrackBall TrackMan Wheel Mouse - $30
3) SYBA 4-port mini USB hub - $8
4) BYTECC 10ft USB extension cable (Type-A Male-Female) - $3
5) JB Weld - Had this already.. use whatever epoxy-like compound you have handy
6) Small Zip Ties - Already had this as well, feel free to use twist ties or whatever
Total price: $48 + shipping
Total time spent: ~30 minutes construction time, plus a few hours to let the JB weld set properly