Portrait rotation?

[mattspace]

Hi,

Just wondering if anyone can point me to which adapter models are able to drive a 1920x1200 monitor rotated into portrait orientation 1200x1920 on Mountain Lion.

Also, do the display abilities of these adapters rely on the system's video memory / processing, or are they self-contained? Reason being I was thinking of setting up a 2009 Mac Mini which currently has twin 24" displays, with a 27" main display, flanked by twin portrait 24". The Mini has the processing power I need at the moment, I just want to get all my palettes, asset managers etc off to the sides.

Thanks.