I've always just used a 10 gallon tank (though it's insanely tiny) as it's light and easy to transport. However, you could get a larger bin to use if you'd prefer that! I know there is a bin in the sterilite hi-rise series that would work well as a travel cage (it could be a bit long though) because it's very light and narrow. I'll link it below
https://www.amazon.com/Hefty-113-Qt-.../dp/B01DKA35TY