75 or 100 gal aquarium for rodents!!!

So I had a pair of gerbils in a 10 gallon aquarium (was told that was appropriate) but realized later it was not. I got a tank topper to double the floor space while I looked for an affordable bigger tank. I'm finaly getting one today, the seller dosnt know if its a 75 or 100 gallon but I'm so excited its huge! But my question is what all rodents do you think I could keep in there? I love my gerbils but I don't think I'll keep gerbils again, I'd love to go back to mice.