It's the safest way to begin imo and a great choice for your first investment.

Keep in mind that those loans with be full recourse (you have to personally guarantee them).Other food for though would be, if you decide to get into larger deals with loan balances over the $1MM then you can get non-recourse agency loans and it would be unusual for it NOT to be in an LLC.

As far as the loan, I was considering going with a Military Choice loan from Navy Fed as they do not require any money down and will do 100% financing to include fees.

I have a larger set of 20 panels on my roof because my house is a two-story building with 3400 square foot.

The house is old as well, with some issues (all 3 furnaces will need to be replaced within 3-5 years).What would be the wisest choice for a first investment?

That being said, many of the smaller towns along the coast and inland have a smattering of multi-family properties, which may be a better choice if you're concerned about school district, etc.

For larger repairs, perhaps having them pay over two months is easier for them and you still get the money at the end of the day. 

You'll never get as low as your number until you move to larger complexes.When I reran the numbers I came up with $425/month cash flow, which is pretty good for a duplex. 

There may be some, but the larger ones who manage in and around Cincinnati I doubt would manage due to the distance for them and their maintenance people.

Some larger banks will lend to an LLC for clients who have a decent amount of assets with them