hello list!

I'm developing a building size installation and now i have a little big problem. Usually i'm using matrox dual head connected to my mac book pro to split my 2048*768 external desktop in to signals for to separate 1024*768 beamers. This matrox works smooth without problems. Now this building is taller than wide and my screen should be 1024*1536 (two 1024*768 placed in vertical). That's means I have to put my projectors in vertical stack.

There is a external box (similar to matrox dual) that split the image for me???

I'm considering the option to buy a new windows based pc to do that, is there  a commercial nvida card works for my needs???

any help will be appreciated