Rewire... create an instrument track in protools or audio track whichever. I personally start out with an instrument track. This allows me to continue to make changes to the music, until i'm ready to finalize it. I then dump them into an audio track which i then can add plugins to... fix audio problems or whatever.
Rewire even if you have all your stuff sequenced in reason. That's exactly what i do... i use reason as the production tool and pro-tools as my recording interface. Once you rewire them.. reason acts like it's part of pro-tools via rewire. All you have to do is when you add instruments in reason is route them to a channel. You can then select which channel each one is on in protools.
Demi