I’m a fan of SFR due to lower turnovers, higher appreciation and much easier to sell.

To me the quadplex would be dual purpose, while you are not living there it serves as a reliable stream of income, once you move there, you could live in 1 of the units while you build your permanent home, and you could also use it for when your family comes over for large gatherings.A 2nd option might be to build an RV park, Unless their are zoning restrictions, you should be able to build one fairly inexpensive, with a septic system and either public water or a well, you can keep your costs to a minimum by doing gravel roads, which are easier to remove later if you don't want them. 

You are well structured to use the debt snowball to pay down houses quickly, and appears from what you have written that this would be in keeping with your current strategy.  

Every system you try will have flaws, or you may salivate over a feature that appears in other software.Some familiar names are mentioned frequently: Stessa, Apartments.com, RentRedi, TenantCloud, Innago, RentManager, Avail, Rentec Direct, Doorloop, etc.I recommend conducting thorough research on each app online to understand their offerings, pricing, etc.

I don't love bookkeeping but this has made it so much easier for me and if I can use it, anyone can.

I would just note as a lender - its going to be much easier to find financing (and have more options) if the property is more of a traditional SFR / residence versus a cabin or creative type tailored STR property. 

Some contractors have insurance, some are 1 man band with no overhead, quality of work factors into cost, level of finishes.We created a calculator for our clients to use here in Chicago, specific to our renovation pricing, but even that is just a guess based on some assumptions.If you can find a quality general contractor, pay them like @Bruce Woodruff mentioned, and it will make your life so much easier...you may eat into some of your profits, but being able to rinse and repeat with someone you trust is priceless!

That will make it easier for renting the long-term rental for sure because you can advertise the base rent, which is comparable to market rent, and then state that utilities are included for the utility fee.

I agree with previous poster that the areas around GVL may be easier to get into.

They’re easier to qualify for and will allow you to bypass personal income/asset tests.Let me know if you have any specific questions about Montgomery—I’d be happy to help.