Why is the score so low? What the negatives are and how recent they are, are just as important as the score itself. How about positive tradelines? How many and how long?
Go speak to a Broker and try to pay down some of your balances on your cards. That is really driving your score down.
Fewer and fewer lenders are doing 620 loans. It might be quicker to pay off some credit card debt now, wait for the new balances to report, and then get preapproved. As it will take the same amount of time (or less) than it would take to find a 620 lender. You say this needs to be done today so today I would pay your balances down even if you can only do 10%, it will help. Wait for your score to update and if it is at least a 640, it will be easier to find a lender as there are more lenders that do 640 vs 620. Once you are preapproved, continue to get those credit card balances down so that you aren't on the edge of just barely qualifying. Most lenders do another credit pull right before closing and there have been folks that were denied at the last minute because their score dropped below the qualifying threshold.
Pay the balances down on the cards that will report updated balances to your credit report quicker. Those cards will be the ones that have statement dates coming out the soonest. In other words, don't pay down the cards that just released a monthly statement and already reported to the credit bureaus, as you would have to wait a month for a score update.
Your credit cards typically report to the bureaus a couple of days after the statement cuts so you will need to pay at least a couple of days before the statement cuts for you to get your payment reflected on your reports for that month.
Fewer and fewer lenders are doing 620 loans. It might be quicker to pay off some credit card debt now, wait for the new balances to report, and then get preapproved. As it will take the same amount of time (or less) than it would take to find a 620 lender. You say this needs to be done today so today I would pay your balances down even if you can only do 10%, it will help. Wait for your score to update and if it is at least a 640, it will be easier to find a lender as there are more lenders that do 640 vs 620. Once you are preapproved, continue to get those credit card balances down so that you aren't on the edge of just barely qualifying. Most lenders do another credit pull right before closing and there have been folks that were denied at the last minute because their score dropped below the qualifying threshold.
Pay the balances down on the cards that will report updated balances to your credit report quicker. Those cards will be the ones that have statement dates coming out the soonest. In other words, don't pay down the cards that just released a monthly statement and already reported to the credit bureaus, as you would have to wait a month for a score update.
Your credit cards typically report to the bureaus a couple of days after the statement cuts so you will need to pay at least a couple of days before the statement cuts for you to get your payment reflected on your reports for that month.
Cards: Orchard Bank ($1100) | Cap1 Cash Rewards ($2500) | Chase Freedom ($1000) | Best Buy ($2500) | Discover It ($1000) | Barclay Rewards ($2500) | Current scores: EX FAKO: 684, CK TU: 649, FICO EQ: 680, FICO TU: 698, FICO EX: 658 Happy Homeowner Since 2/6/13! 
Last App: 4/5/13 Gardening until July 2014