Be very careful telling people you have a large down payment , a lease purchase does not require any more than a $1000 deposit as you would buy any home, do not pay someone all your money and risk losing it, out it in a safe bank account so it is there when you can close.
You are looking for one of several different possibilities; Seller financing, Hard Money Lending or Rent to Own come to mind. You may find a local agent who can help you with seller financing or rent to own. For a hard money loan, you can start with a mortgage broker who may be able to place the loan for you or refer you to a source.
Realize that going outside of the conventional sources for a home loan is not to be done lightly or casually. Hard money lenders charge higher rates and fees and care more about their equity position then your credit. In some cases these people will look for someone to loan to that they hope will fall behind so they can foreclose on a property with lots of equity.
Wells Fargo has lowered their acceptable scores for FHA loans, you might see if you qualify their before taking the riskier options. Best of luck.