The simplest answer I've found to this question is to simply mail to houses that have the minimum required equity in their home.  

Finance is NOT real estate, it is a much more regulated area of business than dealing in dirt and thinking you know finance from knowing something about real estate is naïve.There are accepted, customary methods to do seller financed transactions, proven and acceptable ways to pass through financing to basically assume an underlying mortgage or originate contracts, investors need to stick to them and not get into designing or mixing terms like adding ingredients to a fruit salad.    

There is no quick and simple response.The simplest thing would be for these investors to do unsecured personal loans to you. 

Anyone CAN use those forms though, and that might be your simplest solution.

Duriel Taylor if your duplex is owned free and clear then the simplest way to get the capital for the next down payment is a cash out refi.

That is a key ingredient in your overall success.

This is the simplest method, but it also means your tenants are more likely to abuse the utilities by leaving windows open with the heat or A/C running, leaving lights on, ignoring the toilet that constantly flushes on its own, etc.3.

Not trying to re-invent the wheels but trying to project myself best I can in the simplest manner as I will be contracting directly with subs now. 

Plus, the learning knowledge of working on your own home allows you to gain an understanding of even just the simplest home repairs that you can save money in future work you can do, especially when you are just starting out.

Again, if the purchase prices work with your remaining entitlement to not have to refinance until you hit 20% equity in your current property, that's probably the simplest and cheapest option.