Here is one of my favorite wooden style cages, though do be cautious as gerbs are notorious little chewers
https://www.amazon.ca/gp/aw/d/B01MFF...RyL&ref=plSrch
It holds lots of bedding and is huge, though a bit pricey
Of course, there's also the simple 20 gallon tank, but one half of it should be completely filled with bedding.
Other than the cage I linked above, most aren't suitable. Cages with bars are almost always chewed and this is even more detrimental to gerbils than it is hamsters. As a guideline when looking at a cage for gerbils follow this list:
-over 360 sq in
-avoid bars
-no plastic
-can hold min 10 in of bedding (factor in an 8 inch wheel on top of this)
As long as the cage fits these guidelines, you'll be just fine
