i'm going to hijack this thread just a titch based upon Sandcruiser's (man i should have come to tamarindo to buy you a beer when i was in CR. i was lost and wandering, the one country i wish i could do over) comments about overhauling the motor.
Jilt is sounds like you want to go new and/or reliable (land cruiser) because of a lack of mechanical knowledge. whatever route you take i would suggest someone in your group get some crash course mechanic training. obviously you can service the bikes. a rig is not going to be much different. just bigger and far dirtier. you won't always have access to a forum like this (unless you'll have bgan then ignore me) and it might be put on your own shoulders to fix a problem or even more importantly diagnose the severity of it. two quick examples from my last 5 months.
I started blowing fuses in Peru. Hopped on MUD and did a search. The
answer was one of a few hundred things. I had the basic skills to start trouble shooting each one, one at a time to source the problem. I'm not going to rebuild any motors but i'm not afraid to change my own oil. i'm somewhere in the middle with my skills.
As I rolled into Ushuaia I noticed a noise from my rear end. I climbed around the truck found the problem and more importantly knew it was okay to pull the driveshaft, engage the center diff lock and drive in 2wd for the rest of my trip. I had done the same thing on my way to Alaska a few winters ago.
So you or someone in the truck should have beyond just basic skills. Depending on your route you will find yourself in places where you won't see anyone for days (happened to me on a beach in peru and it was bliss) or where you don't want to see people. either way some knowledge will help. i'm sure you've thought about all this and i'm not telling you something new but along with all your lists i'm sure you're creating (i only had 4, for one guy and no documentary) you need to put this near the top. it will save you headache, hassle and money to work on your own truck.
dmc