TV card? As long as it has comp video in, any should surfice.
Points to note however are:
1) I believe the composite video out of the S-760 is monocrome (Blk&White)
2) You will need to be running the software for the TV card to see anything, which will mean your CPU working that bit harder.

If it was me (and I do this with my S-750), I would run a seperate RGB colour monitor.