Golden pothos is probably your best bet and very common... It is extremely easy to propogate and grows great long vines perfect for climbing. They can be wrapped around anything in the cage also.. I have a couple that have even shot roots through the mesh on a couple cages and climbed that way. Like I said also, super easy to propogate.. I have taken cuttings from pothos in my frog tanks and grown them up super fast to put in a few baby cages.