I will be building a light for my 55 gallon tank.  I plan to start with
two 48" tubes connected to one electronic ballast ($13 at the local
hardware shop) and eventually move to four or more tubes with a second
ballast.  Because the tank is only about one foot deep and I still need
access for my hoses and cords as well as access for feeding, I don't
have much room to put the light (maybe 8" at the most.  I am considering
building the light in a triangle type shape (look below).  Does anyone
have any suggestion as to how this might work?  I also need suggestions
on what type of reflector to use and what endcaps and bulb holders I
should use.  I have been considering URJ products.

        /        \
       /          \
      /            \
     /              \          (note: I plan to mount the tubes on the
sides with the                                       ballast on the top.