High potential here for a big change in situation, needs, and circumstances between next September's 3 week trip (this time with solar) and next year's who knows what when retired (as stated in the OP)
IMO (worth the usual 2 cents), it is time for a "learner set" of solar and then get the "real set" next year or later once the "real situation" is more clear. (The OP might even get a new RV so nailing down a bunch of new panels now would be regretted if that happened.)
It would be handy if the learner panels could be part of the real set later. One 24 or two 12s? Later with two 12s, they could be in series and that in parallel with a new 24. Or be part of a full set of four 12s. Lots of choices.
The big thing IMO is just get a cheapo controller off eBay for now to run the initial learner set this Fall, and then get the more expensive controller later on, when more is known.
I would say get the Solar30 for now, which does have a read out display for amps and volts. Part of the "learning" is to compare what is showing on the solar for amps with the Trimetric for amps, so you can get a feel for how much is battery and how much is load (Trimetric only shows battery, so subtract that from "solar amps" and that is your load amps)
So IMO go for a portable arrangement of panels, not nailed down on this RV, get the eBay controller, and then ponder the whole thing over the winter coming up and then decide on what's next.
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For sure get a 2000w inverter so you can make toast with a real toaster instead of the bread-burner rack on the propane stove! Who needs that? :( (Got ours at Can Tire sale price of $169--it runs the 1000w (output) microwave too)
