another option that is slightly out of your price range, but a very nice fixture for a 55 due to its size is:
http://www.aquariumspecialty.com/catalog/product_info.php?products_id=586
I am running this on a 72 Bow, have had no trouble growing a nice mix of SPS, LPS and Softies.
Antoher benefit of this light is you can sit it right on top of your tank with very little temperature effect, and it looks nice.
I started with PC, and basically threw away $150 bucks when I changed lights. It is better IMO to wait and get what you want.
Good Luck!!
-Brian
