Well first, what shape are your headlights in now? Are the lens on them still clear or have they become clouded/yellowed?
If they are cloudy and no longer clear, look into a head light restoration kit (sold at autostores/walmart/online)
If your bulbs are yellow (its halogen, they usually are some shade of white/yellow unless they are tinted) Typically the "brighter" a halogen is, the shorter its life will be. Philips/Slyvania make some nice ones, you can research on google for what models work well ect. Stay away from ones that are blueish, they are tinted and wont have as much out put.
Aftermarket headlights will not be much of an improvement, some are even worse due to lousy quality parts/lenses/projectors. They may look cooler but not function better or have more output. Fit and finish isnt always great either.
Now the best results will be from retrofiring a proper HID setup into your headlight. That means adding a proper lens/projector, not just putting an HID bulb in the normal reflector housing (the later will possibly have worse out put due to scattering and will blind other drivers since the light is not focused at all.)
A retrofit kit is around $300 and will have the best results. This is an easier model to fit due to its compact size and has a great reputation.
(9007 for the wiring harness.) You do have to remove the headlights from the car and bake/separate the lenses to install. Lots of examples of their output over at HIDplanet.com
(notice that clear/defined cutoff line and the glorious output? Compare that to this; a hid in a reflector
, hot spots and tons of scattering)