I have a 57 plate fiesta zetec s and I was running with 35mm eibachs for a while and they were good springs and was still a pretty comfertable ride and still handled like a dream but a big fat pot hole stopped me from using them Ive now got a set of 45mm killen springs and it still handles bang on the money but its a little bit of a bumpier ride but im used to it
Id 100% go for the eibachs, will make your car look a million times better