if your talking about CAD work go with the quadro. if your talking about gaming across 3 moniters, then you will likely need a geforce 7950GX2, or an SLI/crossfire setup, and a matrox triple head to go.
i want to do this myself as well. but i want a DVI triple head, not a VGA. with VGA your going to be very limited on refresh rate and resolution (comparably to if you had just one monitor on a VGA cable) just in case you weren't anticipating it expect to pay at least $400 in video card(s) as well as for the monitors (if you dont already have them) at around $200 per LCD, plus the triple head to go, which is like $100-$150 (haven't checked in awhile). you might just be better off with one large LCD and a Gx2. i need 3 monitors for some graphics work as well as gaming. its all what your going to use it for.
I have to draw a 3 separate views (onto one large 3k x 1k window) - HD 720p type resolutions.
I'll try to TripleHead3Go route first.
We are currently using a single Quadro FX 4500 cards to power the graphics for now. The X2 version is WAY more expensive and I'm not sure is better than two 7950GX2 w/ SLI... and CAD-type accuracy isn't needed.
ok, you will not get the res you want tho it only supports 3840/1024 (because it uses a VGA cable). but if thats acceptable then go for it. you may not need quad SLI (not saying its bad, its just expensive). you should see if there are any benchmarks for the work your trying to do, to judge what video power you need. exactly what is this for?