How about one of these? It's a 75W Coralife bulb more for SW application, but it says it can be used for FW.
http://www.hellolights.com/24tricfluorl.html But I still like the AH Supply 1x55W. It's just hard to beat.
I'm also thinking of putting in a 1x13W actinic bulb in the middle to accentuate the fish coloration and add in a dusk and dawn period for a couple of hours. Like a 1 or 2 hour block before the mains come on and after they go off. I do it in SW and the animals seem to enjoy that slightly dark period; although I do 3 hours before and 3 hours after. Does the same work with FW?
And if you're wondering what fish I'm thinking of, it's the cardinal tetra. Now just to find a good place to get them from. I'm thinking Drs F&S.