My experiences on M35s are this:
Running and driving is far better than mint body and so forth. M35 drive line parts are typically big (motors, axles, transmissions, etc.). It's easier to swap a fender or broken windshield than a transmission, engine head or something else. Mileage is also a typical issue for some. I dont worry about it. One of my trucks has 60k on it, the other only has 3k. They both work like a champ. Definitely get a truck you can preview if you;re bidding from a govt site. Pics aren't necessarily the greatest and the descriptions can be vague.
Parts availability is pretty much unlimited. You can buy from govt auctions or from any of the numerous surplus dealers. A lot of the parts also convert over to the civilian market.
M35s are still small enough where one can work on it in their driveway with regular tools (outside of motor swaps etc.). And one discovers that in the MV world, you;re truck/project is never finished. Always some other accessory, paint job, etc to be put on.
Cold weather starting Im not to familiar with, being in Texas and all. The cold weather we get in the 30s or so my trucks still start fine. A little more finicky, but not to much. They do offer either kits for them to help with extreme cold weather starting.
Being here in Texas, you try to watch out for the Katrina (or other hurricane) trucks typically because they're trashed. But I think those have all been sold. Winch trucks will typically sell for more than non-winch and be more desirable. Personally, I think it' one more heavy object to worry about and I dont plan on getting a deuce to the point where I need to use a winch. If I did get to that point, I messed up somewhere.
Now one just has to decide on all the options (hardtop, soft top, drop side, winch, no winch, LDS-465 non turbo, LDT-465-C "whistler" turbo, or LDT-465-D "non whistler" turbo). People like whistler turbo trucks over the others just because the turbo is freaking loud. There's really no difference between the C & D motors except noise. Hard tops are actually pretty quiet, soft tops and a C turbo motor can be hard on the ears. I have each. If one wants to do a lot of hauling of junk, a drop side (M35A2C) may be beneficial. As, just as the name means, the sides of the beds can be folded down or removed.
Overall, they make for a great starter into the MV world. They're cheap, the parts are relatively cheap, they're fairly plain and simple to work on plus they're just down right cool.
If anyone has any specifics or anything else the want to know, just ask.