there are a whole bunch of ways you can lower it. but what are you looking for lower seating position or just a scape the can poor handling look? lower seating position on a "s" model is easy get a lower set and adjust the spring rate. that's a cheap fix. or next get a scg front end and rear spring will cost more but your bike will still handle well[up] or and really don't recommend it is pull your front end and take it to a machine and have them cut another grove for the safety snap ring how ever low you want to make the bike. and get or cut rear spring put in doing that to your bike you will have to tightin your spring rate and damping all the up which will make your bike ride like a car with hydros and basically like ****. other thing you need to think about is whats going to hit front fender on motor mount muffler on the ground and so on.
As Squid mentioned - scg parts is the way to go. However if you have a 06+ you'll need the triple tree from the scg (or early r,s,ss) as well since the front forks are 41mm. Don't forget about doing the kickstand.