texas-5-ton

What a great site !! Needed some opinions on a brush truck and hoped that we had some firefighters/ truck guru's that could relate to my predicament. Anyways, we are looking at getting a military truck for a brush truck. I am wanting a 1,000 or 1,250 gallon tank for the bed. Now, I have a M54A2 picked out that is several miles away that I am going to go look at. I guess my real questions are::

1. Is the multi fuel better/worse than the cummins as far as power?
2. What is payload for the 5 ton vs. the 2.5?
3. Highway operating speeds?
4. Manuverablity, Center of gravity, length, height
5. Safety

Thanks for taking the time to review my listing. Any help would be appreciated..

Chad
RVFD