We prefer to make the investment relatively close i.e. 2-3 hours flight max.We want to start small as this would be our first but start at a location where we can then buy more and bigger investments (like an apartment complex) once we have a local team and understand the micro-markets and details. have been considering buying something from roofstock.com to begin with. 

Problem is, 10% down doesn't pay off our home equity loan.I tracked the buyer down and called him, and we sort of agree in principle on a deal, but the details are still fuzzy.

There are details there.

Those two features alone can be worth the cost of a rock star agent but yes, you can buy/sell RE without agents.

However, the devil is in the details, of course.

I would look into their contracts in details.

What else is possible in paving the way for future tenants and setting them up day one with these above features?

Problem is, 10% down doesn't pay off our home equity loan.I tracked the buyer down and called him, and we sort of agree in principle on a deal, but the details are still fuzzy.

Buy something.There's 1000+ details omitted there for brevity, but to your question about "legal steps in terms of financing" that's the general answer. 

Your contractor and home inspector should give you the details on how to proceed.