I was actually planning on a dedicated ISS radio to try a voice contact with the crew albeit probably a rare thing outside of school contacts.
uplink 144.490 downlink 145.800. The Ft2900R is cheap enough to dedicate to this until I achieve my goal.
Yes, crew to ham contacts are very rare these days. Mostly you'll hear school contacts. They don't use the same uplink frequency -- it's unpublished. What I do is add the ISS voice frequencies to my memory bank and include them in scans. That way, if I'm scanning, and I hear anything on 145.80, I know I can stop and be right there in the action.