Purchase, Get Same $$$ Back From Seller As Note?

ARV on house is 120K. Needs 30K in repairs. Will offer 54K so I stay at 70% ARV. Seller only wants 10.4k in cash. He would like to give me a note for the balance to spread out tax implications. I don't have 40.4k for the rehab + cash he wants so I can't afford to do that out of my pocket. I do have a bank that will finance me at 80% of the ARV for a purchase. The problem is the seller doesn't want to pay capital gains. Does anyone know of a way to borrow the 80% of 120K from the bank, the bank would write him a check for the purchase price of 54k, then he would give me a note for the 43.6k he does not want yet so he can spread out his tax liability over time? Is this legal? Other ideas? Thank You, JohnCl