Update: I got tired of looking so I tried to figure out how I could improve what I bought. I bought this model of case (mine isn't pink, but this is the only photo I could find off the net of one that wasn't tampered with):
I tore out the molded plastic inserts and looked about the house for something I could use to line the insides. I looked in my kitchen and I thought about using excess non-adhesive shelf liner material that I used to line my cabinets and drawers. I cut out the dimensions for each side (6.2cm X 9.6cm) and tucked it in under the elastic straps. It works GREAT! I had to trim the corners a little bit, but it keeps two 510 batteries, two 510 atomizers, four 510 cartridges, and a 3ml sample bottle of my favorite eLiquid. The fact that it stays in by itself and can be pulled out with ease allows me to clean up any spills inside the case. I can also wash the material easily, although I don't care to really, as I had quite a bit left over from it's intended use. A roll of the material is relatively cheap. I found small rolls in Target and Walmart for $1.99. They come in many colors, which is nice. My case is black pleather on the outside and it has black non-adhesive shelf liner on the inside.