If you're using keyclone, there will be a drop down menu like this: \\.\DISPLAY1 and \\.\DISPLAY2. Set your monitor 1 to 1920x1200 or whatever the max resolution is. Monitor 2, you'll want 4 400,300 screen sections. Make sure you have the maximizer enabled for them, and set the second display's maximizer resolution at 800x600 since it's exactly the same aspect ratio as the boxes (the size doesn't matter, it will scale to fit).

Personally I would use monitor 1 as the 4 screen sections, as you can get 4 full size 800x600 boxes in there, and use the smaller resolution monitor for your main. That's how I have mine set up when I'm five boxing...