I would recommend a videocard capable of outputting proper 1080p24 through HDMI.
Because you want a judder free output right?
I don’t think nVidia has good enough clocks in their cards to do this reliably yet.
Go for a good HTPC videocard from AMD.I don’t recall ever seeing any judder problems with the output of my NVidia cards. I have read that there may be issues with AMD cards in full RGB mode, though. And you need full RGB mode if you want to avoid colourspace round-trips.
If your nVidia cards can output perfect 23.976Hz, or a multiple of this, then disregard my comment.
All other refresh rates will produce judder and/or dropped/repeated frames for film content.
I have had no personal issues with full RGB mode though.