I have had Eibach springs on standard shocks but it was not low enough at the back for my liking, i then had a set of FK Coilovers fitted and it transformed the handling, but i had a full polybush set up which helped. The eibach springs were not much different from the standard springs with regards to hardness, the coilovers were harder but the bushes were the things that made the biggest difference to hardness of the ride. Your going to get a hard ride when going low, cant say i had any rattles or bits falling off, thats a lie actually my rear view mirror would jump off the windscreen on a big bump lol
£450+ for coilovers anything less will be shite