I know I could go and purchase a 150W CF, but it would never fit in the hood no matter how I modded it.
I think I might just go with 4 15W bulbs, as they will fit perfectly, with only the need for sockets, and it will give me 60W total.
considering the tank is 35, and i have probably 30 useful gallons, that gives me about 2WPG, which is fairly good?
If I remember correctly, correct me if I'm wrong, the tank is a hexagon? If so, look for the add on light kit for a ceiling fan. Home Depot has some that have 3 sockets that are cheaper than buying the individual sockets. I'm probably going to do the same thing you are with lighting my smaller tanks. As everyone else has said, go with the daylights. Soft white is a bad spectrum both in appearance and K value for aquarium use.
I use the spirals on my 10g and it grows just fine. Remember those lights do have a lower wattage and the package will tell you what the comparable normal bulb would be. So if your fixture is rated for 50w don't but a 50w spiral, or you could have a fire.