97-03 GP headlights suck at directing/distributing light, and adding more light won't change this fact. Light distribution has as much impact on nighttime visibility (or probably more of an impact) as the total amount of light.
If you have the money, I'd recommend the Spyder projectors. Even with the alignment problems (they will be slightly "cross-eyed"), they do a much better job of focusing the light than any other solution I've seen for our car. There is a new version available with CCFL halos, but I don't know if they've fixed the alignment problems.
If you don't want projectors, I'd recommend first either getting new capsules or wet-sanding and polishing your current ones. The cloudy plastic lenses significantly reduce the output. Next, I'd recommend a premium clear glass halogen bulb (the Philips XTreme Power +80 is the best 9007 you'll find). These bulbs do produce slightly more light (within the allowable tolerances of the 9007 specification), but also have a more precisely crafted filament, which yields a better beam pattern.
Here's a good explanation of the different types of bulbs out there. Look for the long post from Scheinwerfermann (5th post down). It's long, but it's definitely worth reading.
