You could shoot slow-mo on an HVX200 in 720/24p mode, and dub that over to tape in-camera.
Otherwise, you can shoot in 720/60p mode, and just do a firewire capture (note, *not* 720pN mode, but 720/60p @ 24fps). FCP 4.5 can edit DVCPRO-HD footage, but not from P2.