Adding 4 Golf Cart Batteries

[NotyetMHCowner]

I am going to be installing 4 Costco batteries in the next week or so. I am trying to figure out what parts I need, fuses, breakers, terminal blocks, etc.

I have an Onan generator. I do not have an inverter yet but plan on buying one soon. I don't have solar yet and don't plan on buying any soon (maybe 1 portable unit now) but will in the future (maybe next year or two). I am thinking either a battery switch then fuse, or breaker that will act as a switch as well. I don't know what size to protect the batteries. I then would like some kind of buss bar or terminal block that I can add different size wires to as I go along, possibly one for both the positive and negative. Then a breaker/switch to feed an inverter. I am planning on buying a 1000 to 2000 watt pure sine wave inverter from somewhere like Northern Tool and just run an extension cord to the living area to plug in whatever we need at the time. My plans for the long term is something like a GO Power solar kit with the inverter powering everything in the rig, but that will have to wait. I am not planning on any kind of battery monitor system as of now. We will only boon dock for up to 4 days for now anyway, and we have a generator if we need it. I will check the battery voltage from time to time with a multi meter at the batteries.

I have found information on Blue Sea components that look real nice. I just need help in sizing the main fuse/breaker and would like some pictures of similar systems. Any thoughts?