The caution about carseats is in extended cab trucks, because there isn't enough room for head excursion. I know the TF forbids installation in extended cabs for that reason. I can fit a Radian RFing at its natural recline behind the driver of a Ford full cab (is that the crew?) with the front seat almost all the way back, like maybe an inch forward. So in a full cab, I wouldn't worry about it, there's more room than in my sedan.
Full cabs give you more room in general and more comfort for the back seat passengers than extended cabs. My dad had an extended cab, then got a full cab. He also got a cover for the bed because otherwise, there is no place to put purchases other than in the cab.
Um, let's see what else you need to know. Generally they are gas guzzlers. Full cab trucks with 8 foot beds are long vehicles, and can be difficult to park. Top tether routing is different in trucks, but I assume you already know that. If you can't reach the tether after the seat is installed (like if you fold down the back of the seat to get access), you'll have to adjust the top tether first, and then install the seat. I don't care for that, personally, but it might not bother you.
I can't think of anything else really truck-specific. Just the usual things like look for lap-shoulder in all positions and adjustable headrests. I think you're more likely to find lap-only belts and no headrests in trucks, particularly big ones that are exempt from passenger vehicle standards. Oh, that reminds me, if it's big enough it might not have LATCH. It may not even have top tethers. Over a certian weight, they're not required, but they might be there voluntarily. I know my dad's 2007? F350 has lap-only belts in both center positions, no center headrests, no lower anchors, but it does have top tethers for all three rear seats.
One other thing, on his F150, my dad had this:
It's a bed extender. (Google truck bed extender.) It goes inside the bed with the tailgate up, and will contain your stuff so it doesn't slide around. Or, you can open the gate, flip it over, and it will look like the picture above, extending the length of the bed by about 2 feet. And it comes off easily (but not accidentally) if you want it off. Dad really really liked it. The only reason he doesn't have it on his F350 is because he tows a 5th wheel.