Not sure what your budget is or what resources are available near you. I'm guessing you are looking for the wood mulches that are made specifically for playgrounds and are refined to create a better mat surface. And depending on the wood, some resist decomposition better than others.
A couple of brands you might consider are:

-- FloriMulch PlaySafe Playground Surface, comes in bulk or bags.

-- Tumblemat
http://www.upstatemulch.com/playground.php

Here is a link that might be useful: Playground surfaces

Southlake is a little bit of a drive for you but there are a couple of places. Tex art Stone on Davis Drive has Pine Bark in bulk. I don't know their prices. They also have a "Kiddie Kushion". Alpine Materials on Brumlow ave has an engineered wood fiber called "Playground Material" for $34. a yard. I can't vouch for either of these places because I've never purchased anything from them but it might be worth a look.