GTX 260 is 10.5 inches long (and so are GTX 275/280/285/295)
The ATX motherboards are 9.6" wide.
Both Sonata III and Elite fit a 10.5" video card without a problem, especially since they side-mount the HDDs (no power or data cables intruding into area where a video card might be).
You can confirm that reading the
NewEgg customer reviews (Sonata III)
In this interior view of the Elite you can see the extra room between the right edge of the motherboard tray and the HDD cage. About a 1/2" to spare with the GTX 260 according to the NewEgg customer reviews.