i want to use lowering springs instead of coil overs to lower my car. but i heard if i just use lowering springs the suspension will mess up over time. so what other products could i add to the setup so that it wont mess up my suspension?

 

When lowering, the stock shocks will blow over time. Some make it longer then others, but it is inevitable.

Would be best to get shocks that are designed to work with lowering springs.

Don't forget to get an alignment afterwards....you don't need camber kits.

 

but will a camber kit help and how about a sway bar?

 

help what?
When you lower a car you get negative camber. You would want a camber kit to be able to adjust it (if you wish to). Some believe you get "camber wear" on your tires after lowering. The toe being out of spec will kill the inside of the tires a lot faster than negative camber. So, was just saying you don't need a camber kit. There is a thread on here that goes over all of this in the suspension forum and IIRC it's stickied.

What about a sway bar?
Has nothing to do with lowering a car.....do you know what a sway bar does?

 

It depends on what you are trying to accomplish. If you are trying to autocross a car with and 8" wide tread then a camber kit will assist you in getting the maximum tread contact area on the road. If you are just driving to the grocery store, then it will cause you more problems that it will solve.