Hi,
I have a Cayenne Diesel from 2012, but would have loved to buy a V8 or maybe a Diesel S. However, car taxes in Norway precludes such ideas. Before buying mine, I drove an old Touareg (2003) with the 3.2 V6 engine which was underpowered and consumed a lot of petrol. That would be my concern re the V8 too. ithas the power, but won't return impressive mpg figures. If you are set on V8, I would go for the GTS which has won rave reviews.
i imported mine from Germany and it is fully loaded, including air suspension. I have never tried the steel spring option, but was told that with 21' wheels, air is required. Mine also has 14 way comfort seats (would probably consider the 18-way sport seats), full natural leather (makes you feel good) heated (front and rear - kids love it!) and ventilated seats, PCM with all the connections, panorama roof, electric tailgate, PASM, PDLS, Bose, 21' Sport Edition wheels with wheel arch extensions, lots of techquipment extras (blackened headlamps, tail lights, alu gear lever, etc.). You can spec a Porsche until your bank account is empty, but when buying second hand, you may as well go for one with most of the boxes ticked. Reliability is much improved with the second gen, partly due to a much simpler AWD system, but also because Porsche learnt a lot from the 1st gen. The interior is great. Motor journalists complain about too many buttons, but that is only because they drive the car for a short test drive. Once you have set it all up, you rarely touch the buttons, but when you need to change things, you don't need to go through an awful lot of menus whilst driving.
It is a fantastic car. We regularly go from Norway to Denmark and both my kids and I love it (my wife falls asleep...). It is a remarkably effortless car to drive whilst at the same time making you smile due to its capabilities. I also have a 997.2 which is fantastic, but at times, I am even more impressed with the Cayenne...
Best of luck!
