krazykoletang, I don't know anything about Graybar's website. To my knowledge, you can only order from their brick and mortar locations. The one closest to me didn't stock those ballasts - they had to order them from Advance. Just call your closest Graybar and tell them what you want and they should be able to get it for you.
Dave, Thanks again for all your help and tips. I don't think that bowing of the top should be a problem. I used all 1x dimensional lumber and the top is a bunch of 1x2s glued together. It seems to be pretty solid. As for the doors, I thought about having the two doors, but I figured 1 door would aid in rigidity. It's kind of hard to see in the picture, but part of the top is actually attached to the front door so that having everything all one piece makes for a really solid setup. I will probably leave it that way because when I open the door (at least for now), I really like being able to see everything from the top and would probably even open both doors just for feeding. I'm just glad to have better access at this point. The only thing bad about having the whole front opened is that it's rather blinding!
Olgranddad, I will take some more pictures of the hood tonight if I get the chance and will post some measurements and specifics then.