Need to provide more info about the subs. Need to give some specs. On 15" rockford fosgate my buddy has he uses a Memphis 1000d amp and it thumps like crazy. He had dynomat customly installed in the ceiling and floors of his explorer because of too much internal rattling.
Any 400w or 500w amp would do as long as it's a Kicker. Seriously though it all depends on how big your box is. You can't go wrong with more power though.