I'd suggest thinking about a winch. I have 44 acres and have been restricted to cutting next to my logging access roads. The kids hate carrying blocks through the bush to the wagon on the trail, as do I, and I find it nearly impossible to get the atv with a wagon in very close, unless I want to clear sll the little trees, etc. Maybe I should do that, I don't know. But I recently bought a winch, in my case for my 3PT on the tractor, and oh what a difference. Up to 150' away, I can drop the tree and drag it in...maybe in a couple of pieces...right to the roadway. I don't think the ATV winch has the power for this...but maybe a winch on the truck? There are other things like capstan winches as well. Just a thought. I think in the end it eould be more productive, but I know 15 years ago it was all just a dream to me (as was the tractor, building a house, and buying the land....)
I would recommend a "gear" type transmission as opposed to the automatics with belts. I think this kind of heavy work, which usually results in machine abuse, needs something solid. I have a Bombardier Traxter...the heaviest atv I could find at the time because I primarily use it for plowing snow from the 900' driveway. Been pretty good for me, but I apparenly did break a front drive axle or something just in the last snowfall...slamming hard into some snowbanks after I pushed them back with the tractor...trying to make more room for more snow!
Try and think a bit about a winch....it is very nice. If not possible, perhaps you can use a rope and pull with the truck. In such a case, a snatch block makes all the difference. Wire rope would be a real PITA, but there's the Amsteel Blue rope which is likely very easy to work with. If you had a helper that could drive the truck, and you could choke the wood in the bush, it might be fairly quick and easy. Having the winch now, the kids and I are extremely pleased to see the log length trees pulled right in front of the woodshed. Much quicker, much easier, and much safer too. Pulling down the snagged trees is a breeze...as opposed to cutting and wondering what may fall upon your head! Just some other thoughts...I didn't seem them mentioned. Be safe!