Hell no on LiPo unless you like fire. In which case just throw a burning road flare in the back seat and hold your phone sideways. Eventually LiPo or it's descendants will replace lead-acid, but we're not there yet, and LiPo fires are practically impossible to put out without a firetruck full of the right foaming agents.
The simple answer is an Optima Yellow top (deep cycle, starting rated) with a blue-sea Automatic Charging Relay to isolate the house batter from the starting battery. A dedicated starting battery with a dedicated deep cycle (I forget the optima colors) is better, but you can't use a true deep cycle battery for running a starter more than a few times before killing the battery.
Whatever technology you pick, move them out the engine bay and make sure to get sealed batteries so you don't poison yourself.
00 high strand count welding cable is probably good for any location on the truck, it's flexible and the higher strand count lowers the internal resistance of the wire, which reduces heat. Conductivity, the inverse of resistance, is based on the total surface area of the wire available to transmit electrons, so more, finer, strands have more surface area per total wire diameter.
Last time I looked (which was pre-covid) Amazon had the best prices on all the stuff you'll need to do a battery relocation and "big 3" wiring upgrade in the engine bay.