Not really sure how to go about financing but we're planning on having a down payment at or slightly above $100,000 and don't want to pay more than $3100ish per month. 

They have no cash to qualify for a rental or even pay for the move. 

And it can work really well for you as long as you pay attention to the statute requirements.In order to defer all tax you are selling investment real estate and buying investment real estate of at least the same value you sold. 

Investing OOS for the first time, and using a TK provider for the first time.I understand I'll be paying (significantly) more for a TK provider home.

You can buy a 250k property with 25% down and pay about $1600 in PITI, or 350k / $2100.

Who would be responsible for paying this?

You can structure the deal to pay him gains at a zero federal tax rate.  

https://www.treasurydirect.gov...I know you asked about cd's , but the IBond is currently paying 6.8%.

It may sound nice to pay a 6% management fee but the extra fees can add up to be more than the other company that charges 10% with no additional fees.

When I have last minute cancellations, I still pay them.