Light - Which Bulb?

["Giancarlo" <gp at isaconsulting_com>]

Hi Everyone, I thought I'd post this question here to see what people's 
thought's are on 'which bulb to use'. I'm just getting back into aquaria 
after a few years of travelling and being unable to set one up for any 
period of time. I'm setting up a 55gal tank with a double 40Watt fluorescent 
fixture (the all-glass one), I know it's not a lot and I'll retrofit a CF 
setup sometime in the future but for the time being this what I have to work 
with. The problem is which bulbs should I go with. I looked at the data 
here: 

http://www.geocities.com/Heartland/Hills/2637/spectra.html 

Having just under 1.5WPG it would make sense for me to go with the higher 
lumens such as the PennPlax Ultra Trilux, Philips Advantage or Coralife 
Trichromatic. Neither of these bulbs are specifically marketed for plant 
growth such as the Coralife Nutrigrow. On the other hand some people have 
suggested that I go buy some $7 tubes from Home Depot. There seems to be a 
lot of people using all sorts of lighting these days and I find myself a 
little lost when selecting mine. The LFS is obviously no help, they just 
suggest me what they sell. 

So what's the big picture? If the difference between a 6500K Home Depot tube 
and a Coralife Trichromatic 65000K tube is just the spectrum (and price!) 
what advantage does one have over the other? 

I've used specific grow lamps in the past but wasn't too crazy about the 
reddish glow they emit, I much preferred the bright (bluish) sparkling water 
the 65000K gave me but I forget what brand I used back then. Regardless of 
my preference I do want what is best for my plants, at least until I can 
better my WPG. 

Any suggestions? I haven't seen many websites with tank photos indicating 
which bulbs they use. Any info on this would be greatly appreciated. I don't 
mind spending the extra $ if the Coralife bulbs do indeed carry some type of 
advantage, just don't know what that advantage is. 

Thanks
Giancarlo