What Inverter to get? What does it eliminate (other components)?

Seems like the “victron multiplus II 12v, 3000w, 120amp” is the starting point for my solar RV / Travel Trailer build? I know that it has a ‘charge controller’ inside of it. Does this eliminate the need for upgrading the Travel Trailer charge controller? I do believe that I’ll still need to purchase an MPPT Charge Controller but wanting to confirm – as the names are, the same. Are there any other solar array components that I would be able to skip or not purchase if I have the Vic Mult II?

Wiring this Inverter into the trailer, is it simple? Or hire an electrician? I know these are able to wire up a ‘2 sided’ solar setup but that gets confusing fast. Would the existing charge controller in the RV be eliminated and removed, and wiring this unit in it’s place?

In a few months, I will be living full time in my 22 ft travel trailer. This will be my 3rd solar build and would love a recommendation on where to ‘begin’ as I’m not a beginner but need some good advice on components and were to start? I’m probably going 12 volt because I know 12 volt.

My first 2 purchases would be the Victron Multi Plus II and a 280 ah Chins ($414). Any advice on what components to start with? I’d like to build a system that I can add additional batteries and panels in the future …

Thx!!