The Battleborn are expensive, but are guaranteed for a long time and have a good reputation. They have been torn down by reviewers and the internal construction - hidden from view - is sound. Not so much on some of the cheaper alternatives. You can do a much cheaper version using Calb prismatic cells, but you are now at your own risk implementing a BMS and the appropriate disconnects.
Charging from the truck could be a major problem depending on the alternator and wiring. Lithiums will demand all the current available until right up to 100%. On boats with very large alternators and 3/0 wiring between them and the battery, it is not uncommon to fry the alternators very quickly, unless the regulator has a thermal limit. Most automotive alternators these days do have a thermal limit of sorts, but you will hit it very quickly with lithiums, unless there is another limiting component in the system (like the charge wiring).
On life, you will get the best life if you do not "bang the corners", that is operate typically between about 10% and 90%. Unlike SLA, LFP would rather be in the middle of the charge range - though the figures I have seen show a relatively modest reduction in life. Also, LFP are not supposed to be charged below 32 deg, so you may need to be careful after a cold overnight soak.
