if u are on a budget, get stock replacements or do what i do. get some of that rubber hose stuff (vaccum hose) and feed it through the springs on both sides. you dont need to use alot for it. i hear no squeeking noise from my springs at all so i guess it works just make sure to use some oil to lube it to slide on.
Energy Suspension make's a nice Urathane kit for the front & rear spring's. I run them and NO they don't squeak or make any noise. I would highly recomend purchasing a set for your car. You won't see a huge handaling difference running the urethane isolator's but they last 10 times longer then the rubber one's ever will.
Ive been looking around also. Maximum Motorsports have them for a good price, but since you live in Cali youll get ripped on tax. You can order from Summit also. The going rate seems to be about $58 for the complete set.