Re: Widescreen resolution support.
In order to use a widescreen resolution you need a modeline for the resolution in question and then it works fine. More people have done this before for instance look for threads regarding Apple's Cinema Display and those Dell widescreen flatpanels.
Note that you need to watch out that your videocard is powerfull enough. The problem is that a flatpanel (especially at high resolutions) should be connected using DVI but most boards contain a single link DVI interface which is limited to pixelclocks of upto 150-165MHz. This corresponds to resolutions of 1280x1024/1600x1200 and depending on the modeline some higher resolutions. I don't know what the maximum resolution of the flatpanel is but look into this problem. (All 7800 cards ship with a dual link DVI interface which doesn't have this issue; the same for various Quadro boards)