Here's a simple way to think about it, which is to take credit scoring completely out of the mix. Instead, treat it as a purely financial issue.
Shop around and find out what interest rates you are likely to get, given your current scores. You'll end up with a number. Suppose it is a 9% loan. (Just picking that number at random.) Take 9% of 30k. Then divide that by 12. That's how much interest you will pay on your loan on the first month.
Then look at what you have paid on interest total on all your credit cards in the last month.
Then compare those two numbers. If the loan is saving you a lot of money -- enough that you feel really good about doing it -- then get the loan.
Otherwise, just keep your head down, pay off the highest interest cards first, etc.
As far as scores go, I think you will come out ahead on the loan, but not by much. The negative factors SouthJ gave you. But that will be counterbalanced in all likehood by creating a 1% total utilization with most of your cards reporting $0.
As SouthJ and I said, this is only a good idea if you are SURE you will keep all cards at $0 except one with the remaining card reporting a small balance each month. If you feel you would be at risk for using your cards a lot again, this is not a good idea.
SouthJ also rightly warns you to use a major reputable lender, like a CU. He's right that it is very important not to get a lender that might be tagged by FICO as a Finance Company.
