OP here...(I'm a girl, btw, but no worries :) ).
I appreciate all the info in this thread. I mostly appreciate feeling like there is a group of knowledgable people here I can bounce ideas off of. I know there is no "one size fits all" solution, although I would love if there were. I think the middle option outlined above (identify my components, but find an installer at 2x the price of DIY) is probably the best option for me. I don't want to spend more than I have to, but don't have time to install. I'm not even sure I have time to research the best components, which is why I was hoping to find an installer who inherently used what was reasonably considered current best technology.
I've read enough solar threads to know there's a lot to know, and that I don't know a lot.
I think I'm pretty much leaning toward a roof mount system and likely toward having tilting functionality. Rather just do it once. I'll stick with my current batteries until they croak, then will stick the biggest two AGM batteries under my step that I can. That would buy me added "capacity" due tot the ability to run them down to 80% discharge without ill effect instead of 50% like lead acid batteries (at least that's my current understanding).
I'm concerned that people honk the local installer may be behind the current technology, so I apparently still have research to do on components. Pending measurements of my roof, I'm hoping to put two large (140-160 watt) panels up there. The fridge is right next to the steps (where the batteries are) so 8'm assuming routing thru the fridge vent is going to be the ideal path. I like the shunt idea in order to provide a more accurate reading of the state of charge. I can't help it - I'm an engineer, and I like data.
So, thanks and keep your thoughts coming! (Sorry of any typos, am doing this from my phone and can only see a small portion of the response box.)