Hip Hop Skid Bikes / Hipster Sleds / HHSB

Trying to find a HHSB suitable setback seat post as the lovely Shimano 600 aero post that was only just gonna be long enough that I received this morning is 15mm shorter than expected and just ain't gonna work.
Any recommendations considering I have white frame, black SLR, black Thomson stem, silver Campag front wheel, silver DA crankset, and black rear wheel, that are suitably hip and a min of 25cm?

Nitto S83?

I've always liked their seatposts.