Military surplus isn't allowed to leave US soil after it has been decommissioned. That applies to all military vehicles.
Spence
Completely, 100%, wrong. I don't know where you heard that, but it is very wrong. There is no such thing.
Some equipment cannot be exported to other countries, but there is no law stating that they cannot leave the country on trips no matter how long. Those vehicles that cannot be exported simply have to stay in the possession of a US citizen (ie. it must stay registered in your name). People with M35's go into Canada all the time. You can also go into Mexico with it, but there is a law in Mexico stating that civilians cannot drive vehicles painting in a military pattern (camo). But that is mainly due to the drug war going on down there and a lot of the cartels starting buying surplus military vehicles and using them to get around without problems (ie. getting stopped while transporting drugs, guns, etc).
There is even someone who wrote about his adventures in South America with his M35. He had no problem going down there or back.
I have a US M109A3 and M35A2 which were both legally imported into Canada from the US. There are tons of people up here with them as well.
Yes the the M35 or M109 is a big truck and is not the fastest or maneuverable vehicle out there, but that is the same for most big trucks. Plus you have to realize that these truck are over 30 years old (39 years old in the case of the M109). So you can't expect them to have all the features of modern trucks. But as stated before, the are almost bulletproof and very easy to work on. Plus they have the benefit of a multi-fuel engine which is a big plus if you are in the middle of nowhere. If you need fuel but only have regular gasoline sitting around, simply dump it into the tank and go, no other work needed. That is a very good thing if you are in a remote area where there is no diesel fuel around.
I have an M109 converted into a rv/camper and love it. You can see pictures of it in this thread:
http://www.expeditionportal.com/forum/showthread.php?t=27603
You can also look at buying an MLVW, which is the Canadian upgraded version of the M35A2. It includes a common Detroit Diesel engine, Allison Automatic transmission, power steering, super singles, etc. More info here:
http://www.militarytrucks.ca/mlvw.htm
I highly recommend looking at something in the M35 family. I drive mine all over and not only is it a great truck to go out camping/exploring with, it is also a ******** load of fun
