You will also need to install a seperate controller for the 5speed. The Nitro ECM has an on-board controller only for the 4speed.
If you are tired of your 4speed, it might actually be easier and cheaper to swap in the Nitro 6speed manual. Even though you need to install the clutch assembly, You know it will bolt up the the 3.7L.
It would also be kind of cool to have the only stick shift SLT in the USA.