Anyone use the Farrow and Ball Estate Eggshell (20% sheen)? what kind of primer did you use?

I have purchased the F & B Estate Eggshell that comes in 20% sheen (this is 2011 btw, and therefor the paint is now water based) and I would like to know what primer anyone has used successfully..rather than the F &B expensive primer...also the colour is Brassica...anyone use this colour ? thoughts? Thank you!