If you sell just the land on payments rather than for cash, you could potentially get a nice down and a totally retail price, one payment at a time, which also locks up your money, unless you sell the note. 

So don't be shocked if a.) that was their intent when they bought the place to being with or b.) they just don't want to sell so "capital gains" is an easy way to avoid telling a nice guy "go kick rocks".  

Stay out of the 435 loop :) Also, visit KC first(unless you are already know the neighborhoods).

Nice Peter!

At this point I step in to talk with the father who informs me his kids are only sick at the house, but not when visiting home.

Nice, great points. 

They are a very nice couple, and I want to do everything I can to help.

Very nice guy to deal with in my experience.

I know many on this site will disown me for this but buy a place you can easily afford that is "nice" or "decent".

Not sure if the rental property is in the same location as your location tag but if it is the high desert more or less rides or dies with the overall RE market, you have a lot of owner occupants out there now because they can afford to buy reasonably nice homes out that way but not on the other side of the mountain.