What the BANK has to offer, 20 yr amortization with 15% down or..

[Leonardo A. Monterrey]

I was recently given the option of putting down 15% with a 20 yr amortization or 40% down with a 25 yr amortization on a 1.725 million loan. The 15% down has a CoC of 9% return and 30% CoC return if you include the principle payments. The 40% down has a CoC of 13% and a 23% CoC return if you include the principle.

The property i'm looking at has a 10 yr lease with a rent bump after the 5th yr. I'm looking to keep this for more than 5 yrs. 

Which one would you take? 15% down or 40% down?