What I need?

I am bilding office PC and I whant two monitors how I could be able to have all the communications (internet, fax, e-mail...) on one monitor and work on second monitor, all the time.

What is the moust stabile whay to do this.

With two video cards (please recomend two), or with one that supports two monitors like Matrox G400 Dual head.

Matrox is overkill for that PC cous PC while be used with Word apps, and similar stuff, I don`t need powerfull 3D graphic cards, but I need good 2D picture.

Is there any big problems that I could comeup with this, or is this posible to make under some version of Windows and what windows version do you recomend.

Hope you onderstand my question, cous I realy need answer.