Wow, what your asking for would take pages to fully explain. Lighting is the most complex and diverse options for saltwater reefs. Ill give you a very breif overview
You have four basic types of bulbs that fall under two classes.
Florecent
-Normal Output
-
VHO (Very High Output)
-Power Compact
-T5
Metal Halide
Florecent bulbs will cast light over the lenght of the florecent bulb where as Metal Halide will be a single point of light that will only be good for approxmatly 2 sqft of tank so for a 55
gal tank you would need 2 metal halide bulbs. The classic
WPG calculation is not valid for
MH as a bulb on the left of the tank will hardly light the right side so you could have 5WPG on one side and effectivly 0
WPG on the other.
For the florecent bulbs you need special ballasts to drive the different types. Most
PC ballasts for example will not drive
VHO bulbs. The ICECAP line of ballasts are unique in that they will sense what type of bulb they are connected to and lap each type appropratly.
The acutal amount of lighting that would be best for your setup will depend on the types of corals you want. Its best to design your lighting around the desired corals vs design your coral around your lighting.
Describe the type of corals that would be on your "i must have' list and we can then give you greater hints as to what types of lighting and what ammounts would be best.