It does look very
ACish (down to the 3 holes in the rocker arm to adjust the travel...cool!) The really old XtC ACs had Blacks as well!
There is quite a bit of choice out there if your looking for a 120mm (or there abouts) fork capable of doing what you have in mind.
The first that comes to mine is something like
this ; QR and designed for abuse. They are adjustable but it says 'fixed at 135mm'...might be a bit much but you could have a tinker.
OR
http://forums.farkin.net/showthread.php?t=80180 probably not up to the abuse of the Shermans but alas, a contender?
OR
http://forums.farkin.net/showthread.php?t=79763...if you have the money...I believe you can have a fiddle around with the spacers in these to lower them as well.
If your going new, the best would be to get the Fox TALAS as Bodin suggested as they are a very strong, adjustable and more then capable fork. Alternativly, look into Rock Shox Revalation or even Pike (if your prepared to switch to a 20mm hub...probably not worth it though).
Good luck and ride hard!