I'd go with lots of live rock (80 lbs.), a DSB sump with macros and mangroves, and a great skimmer like Remora or Coralife Superskimmer. You can check out e-bay for some good deals. Here's a link to a DIYer MH. Two on your 55 would be plenty to keep just about anything.

KG

http://aquarium.union.rpi.edu/articles/DIY_MH.html