NOCO makes great chargers.
I've got one in my little camper. It's an older one (there are newer models out now), but it has settings for different battery chemistries and whatnot.
The way my camper is setup (very, very minimally speaking) on that end is that I have a port in the wall of the trailer for a standard 15A A/C cord.
https://no.co/gcp1On the inside of the trailer, this plugs into a basic power strip.
Then my charger plugs into the power strip. Mine charges a 100Ah battery, which is within spec for the charger.
https://www.amazon.com/NOCO-G3500-Ultra ... B004LWVEKSThe Genius 5 is the updated version of it.
https://no.co/genius5I use a Dakota Lithium battery, which has a lot of the extra stuff dealt with already, including a BMS. Yeah, I paid a little more for the battery, but I didn't really have to fuss with it much. Just make sure it doesn't slide around in the spot where I chose to mount it (it replaced a smaller AGM battery, so I had to make some adjustments to the battery containment).
Now, a couple years after upgrading my battery, I'm adding solar (I technically already have a little 40W Zamp suitcase panel that can extend my trip a little bit, and it has a controller built in, so its wiring to the battery is dead simple). The solar bits that I ordered for my setup cost me just shy of $500, which is just a bit over half the cost of the battery alone. Not bad comparatively speaking, but considering that my trailer cost me about $10k to start with, I'm easily at 10-15% of the overall cost of the trailer (more if you count the fridge that is the whole reason I have been upgrading my electrical). If your build is saving you some money on the trailer itself, then the proportion will be higher.