There also must be a yield curve of mortgage specific rates that range from 15 year to 30 year but I can't find much information on it.I know that the 30 year treasury can be used as a proxy but I'd like to find something more precise. 

They have a strong preference for nicer areas and properties, which are not exactly going to be high yield though. 

Also, i'm not sure of your local zoning but if you rebuild - even within the same footprint - you can build smart and maximize the space to get the biggest ROI from your rental property. 

Exactly, it's a tough call on most, especially those that need a lot of work to maximize the potential.They had 20 'buyers' walk through ours but no offers & my wife insisted I low ball it. 

It was a great deal to get my business off the ground and I have since bought another property, which looks to yield another similar profit (hopefully I can cut the timeline down a little on this one). 

They also say that they are on 20+ sites and use dynamic pricing to maximize number of bookings.

You have $550k of equity and are making $53k profit, giving you a yield of 9.5%. 

In one thread I can read about maximizing leverage through 30 year loans and the stupidity of calling leveraged debt risk then I come into another that talks to many of the problems of over leveraging and using BRRRR.

SFH might be the best bet- and as you said - I will likely have to yield to my budget to determine the rest.

If you consider the difference between your total payments and market rents ($750 monthly) You can see that (750 / 52,700) * 12 means you'd need to put that 52,700 into something that was yielding 17.1% annual cash on cash return just to get you to where you are once you increase your rents on the first one.