I see many first timers use a standard Realtor and they make a bad choice because they do not get the guidance they need. 

My answer: Good choice, not needed at this stage in your career Good luck 

They came to the lease signing, only bought one month, so right then and there, I said no deal.The second choice tenant I wasn't too sure about, and he happened to call me, right after it happened and I mentioned that I had someone already but had trouble with the 1-1/2 month security.

When it comes to real estate investing, the choice isn’t the same for all.

If you can spend around $15K to get around $1800/mo compared to $60-70K to get "MAYBE" $2000/mo, I would def take the first choice of the two.

Creative Solar and Solar Choice USA are respected local companies, and you could check with the national leasing companies SunRun, SolarCity/Tesla, and Vivint however I don't think any of the big boys are active in Georgia although I could be wrong about that. 

I hope things go great for you, but putting too much on your plate is not the best choice in my opinion.

If you feel they are a good tenant and decide to cover the cost as a good will, that is your choice.

I'm guessing his reference to a commercial bank was simply a choice of wording for conventional lender.I agree with your position on using variable rate financing - particularly now where lender have build a generous hedge into their fixed rate products.  

It changes the seller's mindset from a yes/no to choices.