Does anyone have experience in structuring a deal with a near 100% seller note? What were the terms like?

Background: looking at a very profitable, yet declining, business (sale price >$2.5MM) from a seller who has deep pockets and an appetite for investing/funding entrepreneurs; I only have 3% available for a down payment. Looking to pitch them a deal where they fund the sale. Given my experience in the sector, and ideas for growth, I believe it is at least worth a consideration from them. Thanks.