I installed the Redarc BCDC40 on my camper before I upgraded the wiring. I was quite pleased with the results, plus it also has a small MPPT solar charger built in to it. I went from charging the camper batteries at around 3-6 amps to charging them at 20-30amps. Honestly, I think that the upgraded wiring wasn't really necessary after I installed this.
You may want to consider finding somebody to do the installation for you. It was not super difficult but it wasn't completely straightforward either. The camper cabinetry comes apart easier than it looks like, which is a plus when it comes to running heavier cables from the power distribution area to the battery. I have a shell so yours may be a bit different. Sorry, I don’t have any pics of it.
You may want to consider finding somebody to do the installation for you. It was not super difficult but it wasn't completely straightforward either. The camper cabinetry comes apart easier than it looks like, which is a plus when it comes to running heavier cables from the power distribution area to the battery. I have a shell so yours may be a bit different. Sorry, I don’t have any pics of it.