I would like to draw on my background which includes a bachelor's degree in Mechanical Engineering, control system design, sales and proposal writing.

You will have to pay for the lower risk with a lower return.I would propose that identifying your own properties, tenant occupied, and putting them under your own property management gives you more control and a higher return.  

San Diego city is in the process of formalizing their STR legislation. 

@Christopher Dunson,I like lists so I am going to drop th responses down to what has been proposed.

I'm not really considering buying it, but proposing some form of cooperation.

Then if the agent quoting wants to propose something different let them do that on a separate quote.

If you think he over is by $13,000 then find someone else to come and give you a proposal.

That is not what he was saying, but if you have some lenders on line that are in your state, send them a spec sheet of your proposed investment and see what they can offer, what terms, what rates, what fees, etc.Building a private money investor network is also key.

You just have to learn how seller financing benefits sellers so that you can propose it to them in a way that resonates from their perspective.  

BTW, I'm working on a few MF 'deal' (transactions may be a better word;) proposals with other parties and the scenario is conceptually like yours, although I'd prefer to just get the K-1s and have everything (every deal) separate... hence the SPEs.