Collagen Would Be A Poor Choice
Even in the hayday of the collagen fillers, which preceded the Hyaluronic acid, calcium-based, and poly-lactic acid fillers etc, it was not suggested to physicians that we use this type filler. It is a bit too firm to fill (pun intended) this role. I do feel collagen is somewhat overlooked since it is great for scars and improving lip definition, but it is not a volume filler at all.
The above mentioned fillers all volumize quite well and I think would be the wide consensus choice....