What companies do you think are the best and worst new home builders in the DC area.  

The worst they say is pound sand, and you no better or worse off than you are today.

In Virginia, things are pretty speedy and we think that worst case scenario, we would have to re-file and it would cost us about a month of rent. 

Yeah, I figure what the heck, it's only $21k, and I get experience with seller financing, and if worse comes to worst and the market crashes before I can sell for $100k+, I still have a cashflowing property.  

That's not the worst thing because you're essentially getting a loan from the US Treasury.  

Move into the worst unit and fix it up yourself while you are there.

Worst case, I don't get funding and have to wait 6-7 months to save up to use personal cash to renovate.

Can be alot of fun and nerve racking at the same time. i have a few rental properties i purchased. i figure the worst outcome is i would have to sell at a small loss.

Obviously without having a specialist come look at it that's a difficult question, so what do the worst and best case scenarios look like? 

It's a great place to invest in rental property (unless you refer to the BP headline study on best/worst cities to invest in).If you are looking to get owner occupied, 30 year financing then 4-units is as high as you can go.