Looking at you layout with induction cooktop, and electric water heater are you sure 200 AH of battery is enough? Lithionics makes G31 size battery that has 125 A rating, it is slightly smaller in size than the Battle Born. I see that you are mounting the Battle Borns on end, Lithionics only allows terminals up installations. Lithionics also has other sizes if you need to increase the bank size. if interested in checking out that route PM me, I am a Lithionics dealer.
DC to DC
Sterling is a standard in DC to DC units, comes at a cost. Unfortunately, you need to choose what size you need up front. One of the positives of a Lithium battery is the capacity for a high charge rate.
As mentioned, a good low-cost unit is the KISAE DMT1250
, it would give you a solar controller in the same unit. One nice feature is that you can configure the output in 5-amp increments, so if your alternator cannot handle 50 amps, you can configure it down with out going to a new unit. It will also throttle itself down in output if the alternator appears not to be keeping up, it does a check every 3 mins. No BMS disconnect is needed, as the KISAR gets operating power from the battery BMS shutdown so does KISAE. They also have a remote display, that can be useful, although it takes a little getting used to on figuring out what you are looking at.
Victron also has a couple of units, the real difference of the isolated non-isolated is that grounds are not tied together in the unit on the isolated. This is useful if you are using shunts to get current data going in and out of the units. If not the non-isolated is a little cheaper. The Victron also donít give you any current data, not horrible as you will have a battery monitor. Another feature of the Victron is that you can parallel units, so if 30 amp isnít enough, and you find you have enough alternator then you can just parallel another unit to get 60 amps.
Not much difference in Xantrex XC and XC Pro , unless you want the extra 20 amps of charger. The Pro also comes with RV-C or Canbus for RVís, which you probably don not need. The Bluetooth remote panel is kind of a pain in that you must pair each time you connect. But the extra cost is worth it when you go to program the unit.
I do not have any real experience with Victron inverters but based on their other equipment it is probably a strong choice. This would be even stronger if you went with Victron for your other choices. All your devices could be connected to with the Victron connect app.
If looking for a Magnum MS2000 Inverter, I have one in the classified section
Good solid unit, with a transformer versus the high frequency switchers.
The Victron 712 is a great monitor, again it would make even more sense if your other equipment were all Victron.
Again, a good choice, especially if staying in the Victron lane. Obviously the KISAE DC to DC has a Solar Charger built in.
A good standby choice is the Grape Solar 190 watt panel, it is made in America and can be purchased at Home Depot online and delivered to store for free.
You are in Bend, so you could support local and go with the Zamp line. One of the units I like is the Zamp 190 dual Mode
. This unit is actually two panels in one, so if you need to worry about shading you can configure the two in parallel. If looking for higher output voltage configure in series.
I would also look at wiring in an aux panel outlet. There are many options for portable units that allow you to park in the shade and still get some solar power. The only caveat is that you want to keep the panel voltage as close as possible.
If cost really is not a roadblock look at panels with SunPower cells
As far as the diagram, a quick glance;
I might go larger wire for the DC to DC and Solar charger.
Do you really need all the breakers, a proper sized fuse will generally do the job, at a cheaper cost? A breaker for the distribution panel is always good.
12 Aux Sockets generally are rated at 15 amps, you might be thinking of USB chargers for your rating.
Most Inverter manufacturers want a Class T Fuse for the inverter.
The duplex wire for your lighting is oversized. You do not have to use duplex for your DC runs, I generally just stick with marine wire in wire loom.
You might want to add a CO detector.
For the AC triplex wire, although it is OK with RVIA, I generally go with marine stranded triplex.