A lot will depend on what kind of rock you get, and if you get a reef-ready system (drilled to allow plumbing for a sump), if it includes any filters/pumps, lighting, etc. Most the 'reef-ready tanks are a good choice, while the kits that include lights and filters are not such a deal--very little of that equipment is needed, and can be done individually cheaper.
For a 55 FOWLR, I would want the following:
Tank. Probably not reef ready--overflows work just fine, IMO. 75-100 pounds rock (probably about 50 pounds of dry base rock, the rest good live rock). Protien skimmer. Sump (20 gallon tank, most likely). Magdrive 6 pumps. 4 AquaClear 402 powerheads. 300 watt heater, or 2 200 watt heaters. For lights, I would likely go with PC, just because of the increased flexibility for adding corals down the line, and there's not a huge cost difference between PC and NO. 3-4 inches of playsand.