2x6450=3 Monitors?

Actually since I just read the Eyeinfinity Thread - Not all 3 monitors have the same resolution 2 are 1080 and the last one is 4:3 (can't remember the resolution right now)
Is a setup like this anyhow possible?
I basically need it do expand my desktop in windows

I run 2x 5450's at work for three monitors so it's possible, however Eyefinity only allows 2 monitors between either card.

Yes this will work just fine. As long as you are using them as just displays you can mix and match any cards and any screens you want. Its really nice to give ie excel and outlook their own screens. They don't need to be the same make or resolution, or connection type.

Eyefinity allows windows to use all 2,3,or 4 monitors like 1 big screen. This allows games to be stretched across all screens. For this all monitors must match. But you don't want to stretch games you just want general productivity so you will not turn on eyefinity.
just plug in your extra gpu and your extra monitor and windows will do the rest.

Just so you know, you will not be able to crossfire them and get 3 monitors without one of the cards being a FLEX version or having displayport. As long as you aren't trying to game across all 3, it won't be a problem.

Which annoys me because the low profile cards (SFF Dell 790) all have the blasted DMS-59 connector to dual DVI.