Congratulations on getting and staying out of debt. It is always a good first step.
A CC that offers a percentage cash back may be an improvement over regular CCs. It depends on the fee arrangements, interest rates and all the other details.
But if you really want to see savings your better off avoiding CCs and debit cards altogether. Many studies have shown that using cash, and the act of physically pulling out and counting cash, serves to make spending more conscious and focused to the point that people who use cash consistently spend less overall. Savings far exceed what cash back CCs offer.
With a CC or debit card paying is so quick and easy that there is less chance to feel the weight and consequence of what your doing. A days wage can be tossed away in a thrice. Which is what the CC companies want. Paying off the bill is, of course, far less quick and easy. This is something the CC companies want you to forget as soon as you enter the store.
Using cash keeps the mind much better focused on the weight and consequence of the issue.
With the money you save every day you can afford to save money the old fashion way: Socking away a few dollars every week in an interest bearing account.