Agreeing with Graham that the type does not matter. To repurpose the existing ones, you are limited to one date picker control and 14 plain text controls. I find repurposing good for small projects and to get a quick result.
Repeating Data Using Document Property Content Controls and Other Mapped Content Controls


For major projects or to use other kinds of CCs, I use Graham's utility or one from Greg Maxey. (I generally have both loaded.) They allow for quick and easy mapping of any CC.