Well you know there better for straight lines so I guess it comes down to how you'll use the car?
If you like cruising and hardly get you foot into it, then a 4-Speed would be perfect for enjoying those great roads you have up there.
You could also look into a Gear Vendors OD unit. 6-Speed TorqueFlite-727 would be great fun, and up to 20% faster than stock!
I'm TorqueFlite-727 man through and through, manuals may be more "fun" to some people but I prefer the straight line stuff, after all, that is what these cars were made for...........corners? By rice.
There are many benefits to an Auto, they allow more torque to be generated off the line, no time wasted between gear changes and are always generally quicker in a straight line than a manual would be in the same car.
nz440r/t