As others have said owning the system via a cash purchase or using one of the many low-interest loan options out there are preferable methods than leasing. 

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?

You really need to have at least one of those, preferably two, and ideally, all three. 

You could be walking away from a good deal because of your financing and personal savings and not the fault of the property.You don't have to put 30% down if you prefer less.  

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.

In southern states, home sales are expected to grow by 6% in 2018 rather than 2.5% (the national average). 70% of homeowners prefer to list with a real estate agent who uses video marketing to advertise their home.Main Takeaways Consider hiring a professional house stager — Heck, why wouldn’t you do it if the house will spend less time on the market and the seller will get 6% above the listed price?

I personally prefer to borrow the money and take all the risk. 

Most commuters to the downtown area prefer to live within the I275 loop of close to it.  

I am also looking for one in the same area, preferably with general contractor license.  

So something I’ve been thinking about - if you acquire (buy or rent) a property that’s far from where you live, how would you prefer to furnish it so that you can STR it?