24 unit apartment loan

[Lana Aks]

A 24 unit apartment nearby just got posted for sale. Everything looks fine, except the price. NYC, asking roughly  12 million. Preferred lender suggests to assume the 6 million loan. They told me there is no way to have 2 separate loans on the same building since no lender will take 2nd position. How would you suggest to structure  a deal and what is a min down-payment and expected interest rate? Thanks