Based on what you've
said about your credit situation, I don't see your score dropping from closing the two accounts, unless you have other cards with high balances, or the card company insists on lowering the credit limits, which could cause your utilization to increase with the balance then being over limit.
Research moderately priced housing options and / or start an open and honest discussion with your
realtor about your credit situation to find a home well within your price range.