yeah i know what you mean... Is it one or two lamp? I'm guessing two... If so, do you want to use T12 or T8? If you're going to install it somewhere else outside your home, I'd use T8. this is becuase if it's T12, a future owner will say "oh, well this light is outdated. I'll replace it", but if it has a T8 bulb, they're more apt to kepping it around. If it's in your house, I'd say electronic rapid start.
Here are my choice pics/recomendationd for you:
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For F40T12/RS (electronic). Try to find something with a high ballast factor like this ballast. It has 0.9, which is one of the best I've seen with T12.
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For F32T8/IS. This has greater than 1 ballast factor and Advance is top notch stuff with ballasts, so you can't go wrong with this ballast if using T8.