A regular surround speaker will do just fine, though either will work well. If you're using a stand, or hanging on the wall, the surround speaker will work better, I think. But if it's sitting on a table or shelf, a center channel will work good.
I don't know that one has an advantage over the other, unless your surround speaker is larger than the center channel. Then it will have bigger woofer(s) in it, and may sound a little better, in the long run. Good luck!