We used that loan to put down on a 4 plex we bought in our SOLO401K and borrowed the remainder from a traditional non-recourse lender.

We live in Atlanta and still considering doing a traditional rental for our first property here (or maybe Nashville), but leaning towards the vacation rental due to higher potential revenue. 

There's a tradition in Pittsburgh for a lot of the 1890-1920s city houses to have been built with a toilet and a vanity in the basement, a "Pittsburgh potty." 

Or hold out for a traditional offer from a buyer?

If you're an employee your options are what your employer offers, regardless of whether they're for profit or non-profit, and IRA contributions.Maybe you can also contribute to a Traditional IRA. 

Even if they are accurate numbers, the deal doesn't pencil at the low end of your projected sales price.Hire the right team, AND have entitlements in place before close on the land.Consider more traditional A&D lending, 500k down with the seller seems steep. 1 year max is asking for trouble, especially if the clock starts ticking before entitlements and permits are complete.

That's why in northern climates they are rarely used unless there is baseboard heating or geothermal heat pumps.If you have gas at the house, I would see if you have enough gas supply to put a gas furnace in, and either go with a traditional AC unit or else put a new heat pump in and supplement it with bas or baseboard heater.

Can you not get a traditional loan on it?

I could go with traditional checks but I'm really looking to automate the process.

This gets you more of that personal service you're looking for and they would be more willing to accept your terms than a traditional PM.