Hey Phil, welcome to the forums!
Sounds like a pretty good plan and your smart to plan things out ahead of time! Post what you're thinking, show your calculations and someone else in the forum will hopefully give you a reality check or offer alternatives.
The first thing to do is an energy audit of how much power you'll need, that'll let you figure everything else out.
@FilterGuy has one you can download at
https://diysolarforum.com/resources/system-energy-audit-and-sizing-spread-sheet.12/
From there the
Frequently Asked Questions post has a lot of links that will answer the most common questions you'd have (e.g., how much battery do I need, how much solar do I need, how do I arrange my panels in serial/parallel, what gauge wire do I need).
...3. I have no problem buying a system that can be expanded to my future use vs on the road use.
There are two basic systems you'll hear about:
- Microinverters: Common on homes. These are small devices, usually 1 per panel that go underneath the solar panel and convert solar energy into AC power directly. They're the cat's meow in terms of scalability as to grow you just add one. They're nice as they typically have 25 year warranties, are easy to work with, have no single point of failure (if one dies, the rest still make power), you don't have to worry about designing your strings or a single panel in shade bringing the whole string down. The downside is they won't work without being grid tied or hooked into either an AC Coupled solution or an AC battery designed for them (e.g., Tesla powerwall, Enphase Encharge). It's hard (impossible?) to DIY AC batteries to work with them safely as they use frequency shifting to curtail solar power output. You can typically get per panel diagnostics, so trouble shooting issues is relatively easy.
- String Inverters: More common for RVers. By arranging solar panels in series and parallel you create "strings" at voltage/currents compatible with a solar charge controller (SCC). The SCC keeps the battery charged and the battery feeds an inverter which converts the DC to AC. Typically 5 year warranties and a single point of failure. They're harder to grow over time as once your hit the inverter limit you need to dispose of the old one and get a new bigger one (you can avoid this with planning and using one that has a "parallel" feature). Adding batteries over time has some downfalls AC batteries don't, but is DIYable. Typically you can only get "string" information, so diagnosing problems can be difficult.
You've probably seen the term "All-in-One". These are string inverters combined with a solar charge controller, battery recharger, and inverter all in one device. They're popular for RVs as they generally have a smaller foot-print.
...It seems EVERYONE likes Battleborn - OK w me...next should I do a DIY or buy a Titan or other all in one?
Battleborn's are great products. One of the reasons to go DIY on a solar generator is to take advantage of low-cost LiFePO4 cells to build your own battery. Will has videos on most of the solar generators and their issues, also videos on how to build your own you might enjoy.