If you want to keep a wide variety of corals...plan on Metal Halide lights. I have a fixture that combines both blue actinics and Halides and hangs over the tank. If you have a hood, then a retrofit unit would also be a good way to go. depending on how "handy" you are you could buy a kit and wire it together yourself. I didn't trust myself so we went with an all in one fixture...which is quite spendy, but is "plug and play".
As for the sump and filtration...they are as simple or as complicated as the owner wants them to be. For a long time Kevin (@ Aquatic Dreams) had a 125g system set up in the store that a customer was selling as a complete package. The sump consisted of a 55g tank in the stand, refugium light hanging over a clump of macroalgae, and a skimmer. The tank was packed to the gills with corals and fish and looked spectacular IMO. So much so that it was the "model" for how I chose to set up my 150. My sump doesn't even have a bubble trap or seperate chambers for the refugium. It it totally up to you. The basic principle is the same, you want the water volume to flow through the sump, get skimmed, get some O2, and return to the main tank. You should shoot for the majority of flow to occur in the main tank via powerhead(s)
Right now I have about 900gph from 3 powerheads. 1 located on each side...and one in the back. My tank is also 6' long. Hopefully in the not-so-distant future we'll be removing all 3 of them and installing a SEIO 2600 which will be placed on one end. I like the idea of a wider path as opposed to "direct jet" that most PH produce.
Good Luck...and post some pics...we all like to see how others do it.