There is no clear cut answer to this question. Your credit score is not good at all. No matter what card or loan that you apply for, you will end up paying higher interest rates.
The best way to get lower rates is to increase your credit score. To increase your score, pay your bills on time, stop charging as much as you do now, and try to pay off as many cards as possible.
600-630 is a bit low to qualify for many credit cards. However, there are credit cards that are designed for people like you. Here is a list of cards that you can apply even with poor credit score: http://www.creditcardatoz.com/bad-credit…