Sure! I got this 32GB Sandisk class 4 and it works like a champ! I can now save video at HD settings. I got 2, one for me and one for my wife's phone: (SanDisk 32 GB SD HC micro SDHC Class 4 Flash Memory Card). Search Amazon.com for this, they are around $30. The class number and performance is different b/w manufacturer...as I don't think Sandisk even makes a "class 10" (it's like comparing LTE and WiMaxx when you talk about 4G). These cards DON"T need to be formatted. You just plug in your phone, copy the sd card contents to a folder in your PC, then copy the contents of this folder back to the new SD card. This card also comes with a card reader that looks like an orange USB Thumb drive.
Also, while you are at it, upgrade to the 1800ma battery that came with the Samsung Epic Touch. They are on Amazon too. I got 2 of those.
Once you are all upgraded, you can root and upgrade your ROM to a custom or just FC09 (be sure to use the GPS_Fix.zip if you stay on stock). Almost a new phone!