Should I go with 35w or 55w for headlight HIDs?Don't do LED. LED's will only point light in the direction the diode is facing. Your lights won't be focused on the road and you'll have less visibility than you have with halogen bulbs. If you get the HID's make sure you aim them at the road properly to minimize glare.
Dopeyrsx is right, retrofits are the correct way to do it. If you can't do the labor yourself, these guys will. You have to pay to play.
Also, does anyone know if Opt7 is a good brand for HIDs? I checked retro-solutions and they are twice a price compared to OPT7. I've heard that OPT7 is good but I'm not sure.