Jay Honeck wrote:
I want to add a second monitor (dedicated for the panel), and use the
104" projection screen for the "out-the-window-world-view" only. This
means that I need a video card with two video outputs.

Not necessary to have a dual video card.

An option is to use WideFs and a cast-off laptop/desktop for the
instrument display portion. There are free and not-so-free standalone
instrument panels, that use widefs to communicate over a net with the
core MSFS machine.

All you need is an extra cheap machine and a router.

For non-free example, see the GA IFR panel under Software at the
Project Magenta site:

http://www.projectmagenta.com/

Regards, Kev