I just drew up some plans to have a machine shop make a custom holder out of plate steel that will be covered in foam and upholstery and the computer will be strapped inside this case.
This shell has a steel frame a few inches bigger then then most computers and then will be covered in foam inside and out. so that the foam is compressed when the computer sits in it the steal case is open in the front and back except a small 1/2 inch bar. that will be moveable and it will cover the bottom 5 inches of the computer and will be strapped into place i will still be using a solid state hard drive with this setup i could likely use a normal hard drive unless i hit a bumpy road and i am sure i will do just that from time to time next is seating i am thinking a captions chair will do nicely the LCD screen will be wall mounted like it was a tv wireless keyboard and mouse sometimes you just have to go custom