HUMMER Section: Surplus Military HMMWVs
Now the long answer is that it is possible to find some. As mentioned above, an unmolested HMMWV is illegal and can be seized so be careful. The second option is to build (or purchase a built one) from scrap pieces. The frames can be welded together and pieces gathered together. The last price I saw for a vehicle like this was within a few thousand of a used HUMMER so...
Be sure that you can get a title for the vehicle and prove the salvage. Some states may or may not allow registration of the vehicle. Check your local laws. Note that the military trucks are not DOT approved so might never be street legal.
I know it stinks. It would be great to have a surplus truck if they could be had for a reasonable price.