First off, is this the place to request someone to do one?

Also, for an average pet overlay, how much would it cost and how much time would it take for someone else to do one? Im not familar with them, you see. Please and thanks.

You would request one in the Profiles & Graphics Market forum. :) The cost and time depends entirely on the person who you hire to make it. There's lots of graphics shop in that forum and people usually specify price and such there.