I discovered that Red 4 works with Io. You can choose the Io in the Red 4.0 Preview preference pane and display the output on your NTSC monitor. You can select Auto Update Monitor from the Preview menu and see your changes as you make them. Very cool.
Thanks for sharing this with the forum. If you are on a Mac, RED should be working with all QuickTime compatible capture cards firewire devices for preview since it's going through QT to display the image.