In the add-on packages for Microsoft Combat Flight Sim - Microsoft Combat Flight Sim 2 - Microsoft Flight Simulator 2002 in particular, the cockpits have extra panels which you can pop-up and move around the screen like this:



Sure - having an extra monitor or two helps - I have three!
Look around - I paid less than AUD $ 150 (USD $ 75) for two second hand 15 " monitors and 2 old old graphics cards. They don't need to be powerful to run these gauges.

I'm running a Hercules 3D Prophet III Titanium 500 on the centre screen - 64 meg of RAM, heaps of power and smoooooth anti-aliasing - lookin' good!

How about, as well as a close up look at the panels:



You get tables for each aircraft showing what panel they have and what keystrokes activate them! (Gotta print these out!)