if the set in question are the ones on ebay off shop called performance 2000, or similar, they are the ones i have. i had some issues with mine but all fine now.
1, the front springs were too big for the cups at the top of the struts

the shop were fine about it tho, i sent them back at their cost and all was sorted within a couple of weeks.
2, it was supposed to lower the car 35mm but its more like 70mm.....i kid you not!!! i cant get down some roads its that low. looks gorgeous but unpractical lol. we are still on 15's tho and standard tyre walls so maybe with 17s and low profiles you may get that extra inch you need to get over speed bumps
3, remember they are cheap, it does handle loads better (no longer like a boat) but it is skippy on occassions
good luck. i sent mine to my mates garage to be done, too cold to mess bout outside at the mo brrrrr