So 2 mp 40s are plenty in your tank on 1/2 flow? Doyou have lots of SPS? Because if thats enough for you in an SPS tank @ 1/2 power then that should be enough in a 6ft LPS/Softy tank. Either 2 MP 40s or two Tunze 6105s. I believe the vortech has a more diffused flow and they are smaller then the 6105s, but the 6105s put out more flow and have been proven over years to be reliable. Vortechs are still pretty new but seems like their second gen are fairly reliable. I'm still undecided on lighting though. T5s or Halides and T5s? Even though the tank is 28" deep I'm starting to think the t5s will be sufficient for the livestock I'm looking at. Just found this fixture. It has 14 t5s and looks pretty nice.
http://www.aquariumspecialty.com/cat...oducts_id=1184
or maybe two of these although I do prefer the first fixture and right around the same cost too.
http://www.aquariumspecialty.com/cat...roducts_id=473