It appears that Trijicon has the 6.8 SPC calibrated BDC ACOG available now. This has been mentioned several times on the forum as a future product from Trijicon but its the first time I have seen it available for purchase on Trijicon's website.
Product information can be found here http://www.trijicon.com/user/parts/products1.cfm?PartID=715&back_row=4&categoryID=3
Product information can be found here http://www.trijicon.com/user/parts/products1.cfm?PartID=715&back_row=4&categoryID=3