Whichever way it goes (6 or 8 speed).... keep in mind the cost of these gearboxes in a few years time when they are out of warranty.
The 6 speed ZF is a common fitment to our Australian Ford Falcon since 2006 (after many MANY years of a bulletproof 4 speeder) and only now are we realising that although a vast improvement in drivability and incremental fuel consumption improvements, the HUGE negative is that these ZF's are completely sealed units, not repairable, and cost in the order of $8 to $9 thousand dollars to replace!!!!! .... not short of the value of the entire car second hand!