You might need a credit score boost, or you might need credit repair. If you are carrying too much balances on your credit cards then this might be causing the 'drag' to your score. If you are able to pay down the balances to 30% of your credit limit this should boost your score right up.
However, if you have multiple late payments and other negative items this is considered credit repair. I would be happy to assist you with credit repair in order to get your credit repaired so that you can qualify for a good mortgage.
For more information you can read my blogs here, visit my website or look for me in the June issue of INC Magazine.
If you like the house, see if it is possible to get owner financing or lease purchase. Check with a lender to see how long before you can improve your credit so you can buy / or refinance at a later time.
I sell houses with private financing at credit scores 560. I don't have properties in your area yet but if you qualify with us, I am willing for find one that matches you. Please visit my website for more details.