If that's what you're really after I would start with the basics of what kind of bank loans either residential or commercial are available to you - not saying this is the best option, but it's a good place to start.

Home 1 is ideal for a fix-and-flip loan to fund the remaining $90K, which I can help you evaluate options.

I would upgrade properties every 12-15 months as allowed by low down payment loans if my significant other wasn’t risk adverse and opposed to moving.

House care, lawn care, condition of cars, street conditions, absence of pay-day loan shops... basically all the things you look for when determining where to live yourself. 

This should roughly take me to 150k per year and carry the loans for land and construction.

Quote from @Burke Atkerson: With over a decade of real estate investing experience and over 100 flips, I now provide private money & hard money loans.

(Auctions and foreclosures can also provide great leads.)With $20K, hard money loans are a practical option, as they emphasize a property’s ARV over your financial history.

10% down 2nd home loan and savings from the proceeds of already owned STR's.

yes, you could use the HELOC as a down payment on a hard money loan, and then the hard money loan for the rest.  

I imagine there is not much of a relationship with the turnkey service after the sale and I would deal with the PM and Loan company directly.