Diethelm,
Whilst the kln94 might suit your 530F, it's not much cop for most helicopters, since it's set up to be viewed from the left seat. I had one, and when viewed from the right seat, the colour display becomes almost monochrome. I put a bunch of Garmin 430's in a few years ago, and they work very well. Garmin seem to have a more intuitive construction, and certainly a better data base than BK.