Well, it sounds like you have a decent down payment but will have to deal with fixing your credit. First, go and meet with a lender and have them review your credit and the issus that are keeping your credt score low. If a lender can't help you, maybe you can meet with a credit counselor that could guide you and tell you what needs to be done to improve your credit.
While you are work on improving your credit, you can keep saving your money. Other options are a Land Contract (since you have a decent down payment), a Lease to Own or a rental for a year to help you build some credit, while you repair your credt.
Your best bet is to go talk to the two people I suggested, so they can guide you correctly, you may not be as far off as you think.