dont lower your car on the stock struts (a strut is basically a shock with a mounted perch for the spring, so the spring and shock basically become one piece to be mounted to the car)

The ride will suffer, probably kinda bouncy... and you run the risk of blowing the struts because they are not designed to ride constantly at a lower height.

Spend the extra money on some struts... if the Tokico's are what you want, go for it... Ive heard a lot of good things about them.

Camber is always an issue when you lower the car, no matter how much or little you drop the car you're going to have negative camber. The consequences not only include uneven tire wear, but handling and traction will suffer as well, if the entire available footprint of the tire is not on the ground the way it should be, then you lose traction, thus your handling will suffer too.

Coilovers suck, unless you are reffering to a complete coilover suspension set-up, which are usually around $1000 or more for the kit.
Coil over springs in general tend to suck, the Ground Control's are the choice if you get them though. All they are is a spring with an adjustable collar that allows you to change the ride height. You will still want to get struts and a camber kit with this set-up.

If you get a complete coil over suspension, the struts are part of the package, from what I know, they are all ready to be mounted out of the box. A camber kit would still be needed.

If you can afford the complete coil over set-up... go for it... but the next best thing is a strut/spring combo.

Also, try to stay away from the camber kits that move the whole upper control arm... they tend to make that control arm hit the top of the wheel well, which is not good. Look for the adjustable ball joint type.