i have to say dude, i had a set a of tein ss in my s13 for a year and they never made a sound or gave me a problem apart from the damper adjuster playing up a bit. it didnt affect the damper rates was just a pain to adjust at times. a mate of mine has had his set of teins for god knows how long but they look pretty damn old and are still fine with no noise either.
i havent really heard bad things about the teins myself, only people wishing they got the higher spring rates!
ive had a look at the greddy and they look really well made and they get a lot of good feedback as well, another great brand is ISC, i think if i were to replace mine thats what ill be getting next. they are built well and for a great price!