For a reef tank you may want to shoot for a little more flow in your tank (depends on the types of corals you wish to keep of course).
20 times the tanks volume per hour is an acceptable amount (more should be sought if keeping an SPS
For a 150 gallon tank that would be minimum 3000gph.
The 1 inch Seaswirls will run you $180 a piece (total $360) and the Dolphin $285 -- from Darin @ Captivereefs (awesome bloke). The total flow is 2100 GPH
For $245 more you could order a Tunze Stream kit TS 12 -- comes with 2 pumps (max flow on each is 3175 gal
per hour), digital flow controller, moonlight and all the bells/whistles -- plus a return pump from your sump (Mag9.5).
Overall flow with a 1 inch overflow (600gph) would max out at almost 4000gph. The Tunze is bloody awesome -- tidal, surge, feeding, nocturnal, chance flows are programable. The moonlight even replicates the 28 day lunar cycle. The hardware comes with a 2 year warranty and the Tunze US rep offers excellent customer support (Roger Vitko @ Reefcentral.com).
I'm in a similar situation, as I don't want a multitude of powerheads in the display. One option is running closed-loops to get a larger volume of flow. My condo association banned me from doing this (worried about the neighbours underneath); so I've had to opt for the Tunze option. A little added benefit on my end is for power consumption -- each pump consumes only 45 watts of electric!
Anyways, it's worth thinking about. More flow, more natural, but more money -- (fiancee is ready to call it off when she found my expense log for the new tank!)
Acrylic, 250 lbs Fiji/Tonga mix, 3x175 watt MH
& 2X96 watt PC
, 1/5hp Arctica chiller, EV-180 skimmer
Brown Tang, mated pair Clowns, 4 Fire Gobies, 13 Chromis, Orangespotted Sleeper Goby
Some corals and inverts yet to be identified!