I have installed a 50 watt HID kit in my '08.
If it's about the look, you'll want to get some lights that are about 5000K in color. That's what I got. That gives you about the same color as STis have. With the projectors our cars come with, you don't get glare like you're thinking. Also, the line stays absolutely crisp all the way across. You'll be really satisfied, and you don't HAVE to get the entire OEM kit. (Don't take this as a plug) Kits that are from reputable companies, like SharpHID from the sponsored links portion of this site, are IMO just the ticket to save some money, but still get performance. Not to say that OEM lights aren't fantastic, just that you don't have to spend as much as you would on an OEM kit. The only thing about a retrofit kit is that with our sealed headlights you do have to drill a hole to keep a clean look and a sealed housing. The kit I got came with the grommet to seal the hole back up, and all the HID kits I've used also had them included. Just be careful with the light color you get. If you get anything higher than 8000K it starts to look cheap (they advertise it as "Exotic") IMO even 8000K is too blue to go for a clean stock look. If you go to 4300K, that's what you'll see on most stock vehicles with HIDs. If you look at 4300K by itself you might even think it's a little yellow, but compare it to a halogen and you'll see it's more purple. I found that 5000K is a clean, pure white, and only has the slightest hint of blue. It's just really clean looking, and that's what I like. I have a 6000K kit on my wife's car, and that also looks good, but I find myself drawn to the color of the 5000K setup. I hope that helps. If you have any questions regarding the install, please feel free to ask.