Actually, most Euro's came with the 3.1L. The 3.4L was an option, and the door of the car actually says 3.4Euro, unless it was debadged. The car that came stock with the 3.4L is the Z34 (not a Euro, according to some enthusiasts).
The maintenence isn't that bad, as long as you stay on top of it. If you neglect that engine, it will bite you...hard. The parts for that engine seem to be getting scarce (even at the dealer). Its not an engine I would recommend to someone who was not an auto enthusiast, or who was unwilling to do the work themselves.