I agree with Bill and Tim. It's possible to do, but usually only benefits the seller. Work on your credit, save for a downpayment, reduce your debts, and then go buy a house the old fashioned way.
Have you even talked to a lender to find out what you qualify for? Sometimes people are surprised to find out that they are qualified to buy. Let me know if I can refer you to someone who can see where you stand. If you don't qualify yet, they'll be able to tell you what you need to do, so that you do qualify down the road.