Should I DIY, buy a kit, or maybe not even bother?

[J.P.M.]

I started reading it the first time you recommended it, thanks for pointing out it’s available for free. For future readers, I found it on the https://archive.org website, where there was no BS to download it. It’s almost 400 pages, I’m only in part one but from the index it looks like the book covers everything you’d want to know before diving in.

Understood.
It's a good primer that will pre-answer a lot of questions.
After the read, questions you ask here or elsewhere (including those asked of peddlers) will also have more meat on them making the responses that much better and informative.
Read it and you'll probably know as much or more stuff that's important than most all of the peddlers who scam the solar ignorant.
Knowledge is power.
Most of the screwing by solar con men is enabled by consumer ignorance.
The book is a good start on filling the ignorance hole. The end result may be a more fit for purpose system.

An updated (but now also maybe getting a bit long in the tooth) hard cover version is also avail. at bookstores/Amazon for ~ $25 U.S.

Good luck.