I'm considering buying the FarmerGPS guidance software and don't currently have a laptop.  I have done some looking and see that the Panasonic Toughbook laptops have sturdier frames and cases, touchscreens, and specially mounted innards.  I'm not that familiar with what's available and I don't want to spend much money (used is fine with me and under $500 is even better).  Are there other laptops with similar or better features for this application?  Would I be fine with just a regular laptop well mounted? (I can get a lot more features for the money if I go with a standard model)  Are there particular units out there to consider or stay away from?  Any and all suggestions are appreciated.  I want to use this to spray and the tractor that I spray with is a Case 2096.  It's a decent tractor, but things do seem to get dusty in the cab, and it's not the smoothest riding tractor I've been in.

Thanks,

Mike