A note on the flyable F-16 variants: each has its own different and accurately modeled cockpit. These were done by Aeyes, and are outstanding work.
As to stuttering, I have flown Falcon FF3 on a 3.4 ghz Intel rig, and it has a few moments of stuttering. From the reviews I have read, Allied Force has significantly reduced stuttering. Reports are that it is only a noticeable issue in out of pit views close to an airbase where many objects are being rendered simultaneously. This is an early read, but my guess is that Allied Force should run very smoothly on your rig, certainly better than FF3.
Kazman