I would seriously look at this option if I was looking to retro a hood. (Look at 8th and 9th from the bottom of the page - SUN BLAZE)
http://www.prairiereefsupplies.ca/index.php?id=95
I retro'd these into an aqualight pro (replaced the painful PC's) and I can tell you the increased light makes a huge difference.
They come with a ballast, can be daisy chained together (so only one plug in required) and when you buy the individual reflector you get great lighting for cheap.
Just my 2cents though.