Suspension?

[some cook]

A while back, after searching through ebay, I came across a complete set of new Bilstein dampers. Attracted by the price, I bought these with the intention of refreshing the old Bilstein units....why you may ask, especially since there is nothing wrong with them but I guess im just one of those fussy types. I opted for the Eibach Spring Pro Kit, which has now arrived but im now having second thoughts before having this setup fitted. Fully aware that the original WR Sport setup consisted of Prodrive spec Eibach springs, I am now torn between changing these for a set of P1 springs but unaware as to what, if any, the differences may be? SIDC I need your help.