DIY lighting

Hello all this is my dilema:
    I have a 20 gal tall reef tank with a 2 light hood. I want to build 
a 4 light hood. After many hours of searching the net, I have found very 
little on how to do it.
    The aquatic-plant archives have alot on ballasts etc. However it's 
all in pieces. Does there exist the info all in one place about how to 
wire and ground the ballast, and pretty much do the whole thing?
    I know some of the list subscribers have done it. can/will anyone 
tell me how?
    Also, I have a Graingers 15 min. away. I know they are wholesale 
only. Do I need just a business name or do I need some sort of 
        Thanks for your time and I hope a project for a reeftank is not 
considered a waste of bandwidth.
                           Bigbida at worldnet_att.net