Apartment syndication- prove down payment $ to owner?

Hi everyone-

We are so close to getting our first apartment syndication deal under contract! They seller likes our offer price, but he wants to make sure we are the 'real deal' and can come up with a 20% down payment. He doesn't want to close until January for tax reasons, but he wants us to prove that we can come up with the 20% down before he even signs the LOI. Has anyone ever come across this before? Any advice? I'm not sure how I can prove the 20% until investors actually invest their money, but I don't want to lose the deal.

This will be my first syndication, therefore I am pretty sure I will be hustling to come up with the investor money totaling at 1.6 million, and a 20% down of $957K  all the way up until closing... the only thing I have to offer right now is my word, a contract contingent upon financing, and maybe the $200k earnest money.  

The seller also wants us to show our financing terms that we are looking for from a bank, because he says if a bank can't finance the property, he will carry the financing.  I am okay with this as well, but I don't know how he's going to feel about our plan to sell after 5 years.  

Thank you to anyone who has any advice, I appreciate all the feedback I can get.

Steph Martinson

martinsoninvesting.com