Having just gone through this experience with my syrian hamster, I would echo Biscotti's sentiments exactly! I loved the 20 gallon long, but it was heavy (a pain to clean) and didn't have as much room as I thought it would even with the shelf. With advice from many members on this forum and a DIY instructions from strawberrysmom (
DIY Hamster Cage (Bin Cage) | Hammy Happenings) I went with a 110 quart bin (from Big Lots) that has very smooth edges inside, so Darwin couldn't really get a hold of anything if he tried to chew. I'm so glad I made this decision and I haven't seen my hammy happier! I can fill the substrate pretty full in the back of the bin & Darwin burrows like crazy and the bin is much more portable & easier to clean than the 20 gallon tank
Good luck with your hammy!