Look into Stones bitter chocolate oatmeal stout. There was an interview with Mitch Steele on a recent episode of the brewing network where he discussed what they used for chocolate.
I seem to recall it was actual unprocessed cacoa beans. They actually used them for the bittering characteristics and did not rely solely on hops.
As to the pepper I can't help much. Never played with them in beer though I love hot peppers. If you are going to bottle it maybe stuff a whole pepper into each bottle?