[russell]

If you are trying to make it all terain, then what you might want to consider is getting four large high quality servos (metal gears, bearings and such), and four slightly smaller ones. Modify the large ones to rotate continuously (this is reasonably easy to do. Do a google search for "continuous rotation servo modification" or something along those lines), then mount wheels to them. Then use the smaller ones to steer the larger ones. This way if you want to turn you can set all your wheels to be in a circular pattern and turn "on a dime", much the way the mars rovers do. As far as the wireless connection, if you are good at programming consider using a high power wireless network, which will be able to handle all your data including video over a single link. The controllers we use operate on RS-422 and thus are quite slow, so this probably isnt the best source for information on communications. Oh, and if you are from Egypt (or other places too) your robot will probably be operating in the desert, so make sure that all your gear boxes and such are well sealed so they dont get sand in them. Good luck with your project!