After being an advocate of Koni dampers for my M5, I have recently discovered the Koni front damper on the driver's side of my car is failing. Oil from the damper is covering the strut tube and I'm starting to notice suspension patter over washboard surfaces and minor bumps. The dampers are only a few years old and have had ~35,000kms of easy use.

Having had Bilstiens before (E30 325iS) and finding them to be quite firm, even harsh, I'm in a quandry as to replacement parts.

The car is riding on OE springs and I'm not interested in lowering it since it is already at a nice height. Bilstiens typically jack the front up by about 10mm due to their extreme pressurization so I would fit the thinnest spring isolators possible in order to minimize the ride height change. Internal bump stops will have to be cut down (a well known mod) but still the question: HD or Sport.

Any comments or alternate suggestions appreciated.

Here's a shot of the current ride height: