In reason i would export to wav files, then import those wav files onto an audio track in homestudio. Also if you have homestudio 2, you can use reason via rewire. Certainly cuts back on the whole import/export thing.
- Insert Reason into the Synth Rack using Rewire.
- Set your imported MIDI files up to point back to the appropriate rack device in Reason
- Repeat process for all tracks
- Bounce each track to a .WAV file and mix in HS for the best results.