New tank setup

Well, after getting back into the hobby, and keeping my 20 gallon community
tank for close to two years now, I'm letting myself graduate into bigger
things.  I'm setting up 2 tanks in the next few weeks: a 75 gallon African
Cichlid tank, and a 55 gallon plant tank.

My plans for the plant tank include bottled CO2 injection, but no UGH.

And my question now is closely related to the recently very popular topic on
the list: lighting.

I am deciding between 2 or 3 48" tubes.  The question is, would 2 40W tubes
be "enough" on a 55gal (20" high)?  I'm thinking of an UltraTriLux and a
Triton.  Or should I (make my SO unhappy by making the room look even
"messier" and) put a 3rd bulb there too.  And, if I go with a third one, what
type should it be?  Can I get away with a GE F40/AQ/PL?  Or would a cool
white be better than that?  Or should I go with another UTL or Triton?

As to substrate:  I have bought 100lb of the finer-grained prepackaged
"Sun Stone" brand, aquarium gravel.  Is that sufficient?  And, how necessary
is laterite?

Filtration:  I don't like UGFs, and have been happy with an Aquaclear 150 on
my 20gallon.  I'm thinking of keeping the AC150, and adding an AC300 too.
Does that sound okay?  both in terms of amount of filtration, and amount of
unwanted surface agitation.

All input is appreciated.

Davin Milun    Internet:  milun at cs_Buffalo.EDU
               WWW:       http://www.cs.buffalo.edu/~milun/