Here is what I use, Fits Everything I need unless i take my Drysuit (has its own bag anyway)
Traveler's Club 2-Section Rolling Duffel With Telescopic Handle - Wal-Mart
Its much Bigger than It looks in the picture.....
I Use XL Mares Fins, and an XL Oceanic Excusrion....and Still have room for all the Accessories.