Here's my 2 cents on the lighting then...assuming you go with the 72g bowfront.
If you're sure all you want is soft corals and other low-med light animals, I'd go with a VHO
retro kit with four 110w bulbs...you can get them in either 48" or 46.5" lengths. I would use only URI bulbs in the following combination...2 super actinic and 2 white actinic. I would power them with either a Coral Vue or Ice Cap ballast. PC
's or T-5's are also an option.
If you want to have the higher light corals such as SPS
and possibly anemones at some point, I wouldn't even look at anything less than a 2x250w MH
(10k bulbs)with either VHO
actinics. I would either have a 2x110w VHO
or a 4x65w PC
for the actinics. This is by no means the only thing that will work or the "right" way to light the tank...it's just how I would do it. Perhaps it will give you a starting point anyway.