If you just want truck to truck communications, then 2 meter only will be enough. That's the least expensive way to get started. It's great in every way. It is also much cheaper than a dual band radio. I would not start with a handheld.
I've had my radio almost a year, and I am just now wishing I had a dual band radio, which I will have before our trip through the Maze next spring.
Regarding handhelds-while nice, they are not a substitute for a hard mount radio, and here is why...Handhelds (HTs in radio slang for "handi-talky") do not have the real advantages of the 2 meter radios. They have limited range, limited power, and generally inferior antennas and so have poor reception of marginal signals. A hard mount 2m can go to 75 watts (instead of 5), can have a great high gain antenna, and generally has a better receiver and speaker. In the end, it's all about clarity and range.
Now with that said, the HTs have their uses especially when out of the truck, or hiking. I have this idea to use my truck as a base with a cross band repeat radio, using my HT to talk to my truck on low power, and my truck to talk to the world if needed on high power. I can think of other uses as well.
To me, the biggest draw back of HTs is the fiddly buttons. If you think the hardmount units are hard to program, just wait until you mess with an HT.
I just got back from a great trip to Mojave organized by Scott F. (echo_29). About half the group had 2 meter. It worked so well, and was so much a step up from CB, that fire conversation went to requiring 2 meter radios on future major expeditions like the Maze invasion. We had a similar experience at the pre-Moab run last year, and were wishing everyone had a 2m, primarily for the added range. That, plus the ability to access repeater systems practically everywhere, makes CB seem like a kid's toy by comparison.
Good luck.
KI6CXS