Talk to David Falson at EastCoast Suspensions. He can source the King Springs to do the job. Mine will be visiting there some time after I get it. He was able to give me a great mix setup for the EA to give best ratio of ride heights front to rear.
Yeah the only advice I would give is that you need to consider changing the dampers to match the new spring rate. As most people know cutting springs is a no no, but I have recently been told of a process of heating the spring while under compression to shorten the active lenght. To me this is starting to head in the same direction as cutting.
King seem to be the items of choice for many and they match them to Koni in most circumstances. 9/10 times you will find that they have the damper settings on the softest.