Tirerack.com also sells a drag launch spring for your car, which is even lower that the sportline.
Imo pro-kit is a good for choice if you just want to change the appearance and you dont plan on doing any serious racing.
Will this make my car weird, since it will drop my car unevenly (I realize that the front is higher when stock)?
It is exactly the opposite. The back of cars is usually higher. Remember in the 70's when everyone was raising the front of their el caminos?
As far as a camber kit, you should be able to swing the pro kit without one. Sportline you might want to think about it.