I'd asked a similar question in the past, but my needs have changed slightly.
2 PCs, each with their own primary display on the desk.
2nd display is over hdmi to a projector. We currently have to 'swing' the hdmi cable between them, but I have a switch box on order to resolve that.
What I need to do for at least one PC (both would be nice but not absolutely necessary), is to have that 2nd display output converted to support an additional monitor that only accepts component/composite input.
I ordered the hdmi switch box from monoprice, and their support says they don't have anything like that. If it's not possible, I can live with that, but just want to hear from someone who's had a lot more experience.
In the past, we were splitting a vga output for that second display. One signal continued as vga to the projector (replaced with the hdmi cable) while the other converted through a powered box to a composite cable that used an adapter to run over coax to the same monitor.
Let me know if any of this isn't clear or more details are needed.