I'm assuming the "double hood" is a canopy that holds two strip lights, and each strip hold two bulbs?
Are these normal output bulbs, called NO? With four bulbs that would be 120 watts of "standard" lighting ... how big is your tank, that may not be enough depending on what you want to grow.
Right now compact fluorescent seems to be the most cost effective method of lighting.
With 36" tank, you can use 96 watt compact fluorescents, but you will need to build a hood to hold them - the parts and bulbs to build a two lamp fixture should run you around $150
seems to be seriously competing in the DIY
market right now, offering complete pre-fab fixtures witih bulbs for only $20-30 more than buying just parts and building your own fixture.
A lot of what I've read seems to indicate that PC
lighting is not the best for saltwater because it's colors aren't as pure as bulbs like VHO
or Metal Halide... but if price is the main concern, appearences might need to take a back seat until you can afford an upgrade.
One advantage of building your own hood is you can leave room to include a metal halide bulb in the future, and just run fluorescent actinic bulbs.