@christopherc First thing's first, revenue is somewhat meaningless in this context. Cash flow would be the main thing to look at if you're going to be financing it in any way.
If you're in the US, this is what SBA 7a loans are for.
You could work out a structure where you finance 75% through a 10 year loan (up to $5m) with the 7a program, 15% through a seller note and 10% (the SBA mandated minimum) through equity.
If you're savvy enough, you could even make it so
you don't have to pay for the equity injection by offering an equity step up to an external investor (they pay for x% but get more than x%) or by getting the seller to issue a full standby note. As long as the other parties are willing, you could technically acquire the business for 0 down.
It goes without saying that you need to offer a personal guarantee to do this and risk bankruptcy if the business fails.