I found an Ohlins shock from a 2000 M900Sie that had a remote reservoir at a local wrecker.
The model number on the shock was DU3820.
It had the remote reservoir that mounted under the seat behind the old style suspension height adjuster.
I ended up returning it as it was leaking and for the price they wanted could almost get a new one.
The current model is DU440 and most applications I've seen have it mounted above the clutch casing
The remote reservoir keeps the oil cool and allows access to adjust the pre-load easily. It's not just for looks.
I've ordered a new one from Dan Kyle
Here is a link to a guy on DML who's selling one
http://www.ducatimonster.org/forums/monsters-sale/188177-2000-m900ie-some-tweaks-pciii-dyno-tuned-less-than-3-000-miles-5-100-a.html