You always knew you'd lower it, that was a no-brainer. But how you'd accomplish it, well that was another story. Should you go with lowering springs, a coilover set-up or an air bag set up? Ultimately that's your decision and one that you should make based on a few simple factors such as your budget and what the intended vehicle use is. We'll help in your decision by providing a few pros and cons of each, limitations and approximate costs.
Let's start with the lowest cost option, which is of course lowering springs. Typically a good set of lowering springs will start in the $200/250 range all the way up to about $400. You get what you pay, as with anything. Yes there are cheaper springs on ebay etc, some less than $100. If you're not worried about them being matched to the rebound and compression of your shocks and struts (or safety due to manufacturing cost cuts) then have at it. Now that we've made springs sound bad, let's turn it around: there are some good springs out there, Swift for example. Springs can improve handling and provide that lowered look you may be after. They won't be the best bet for heavy track use, as they likely aren't matched with your springs/struts.
Next up we'll skip right to air bags. What are they? They are pretty awesome if you want a super low car that can also be raised up (to enter parking garages, negotiate speed bumps etc) and also pull some light track duty. You have the ability to raise and lower the car at will with the onboard air compressor and tank. Effectively you have an "air bag" that replaces the springs (may or may not include shocks/struts). Price ranges vary widely, but have come down quite a bit in recent years with the proliferation of bagged cars. Very popular with the stance crew. Prices typically start in the $2000 range and go up with options, plus installation which can cost as much as the parts. Our recommendation is to have them professionally installed by a competent shop or better yet, find some friends who own them that will help you. It's best to get down and dirty with them so you know what to look for when issues arise and/or maintenance is required. It will be, air leaks etc are common and you need to know what to look for and how to fix them.
And finally, if you're a track rat or want the ability to lower your car significantly and still maintain some semblance of good ride quality without going to a bag set up, are coilovers. Coilovers are basically shocks and struts with threaded collars/spring perches. These perches allow you to rotate them up or down, lowering or raising the ride height. Some of the nicer ones allow you to also maintain full spring travel, even at the max lowering, along with both adjustments for rebound and compression via a knob, or electronically from the cockpit. Going up another notch in performance and price, you have remote resevoirs which help to keep the shock fluid cool and as an added bonus, look the business. We have owned several sets of Ohlin's DFV R/T coilovers and absolutely loved them. You can also, relatively cheaply, change out the spring rates on (most) coilovers, which is a nice bonus.
So there you have it--whichever option you go with, make sure you do it safely.