4 monitors on Dimension E520?

Hi All,

I am brand new here and apologize if this has been answered somewhere but I have SCOURED this and every other site and couldn't find a good enough answer to my question:

I would like to run four monitors off my E520 and was wondering if I could simply install two dual head cards as I know the E520 comes with one PCI Express, one PCI Expressx16 and two PCI slots.  This will only be for stock market charts and office applications (NO gaming) so I don't need anything too powerful.  I was looking at "ATI Radeon 9000 64MB DDR 64 bit PCI Dual Head 2x VGA Video Card w/ 2 xCRT and 1xTv out" as they are inexpensive and seem to be what I need.

I read somewhere that my power supply might need to be changed in order to accomplish this.  I don't even know what mine is (read NOOBIE) but would be happy to if that will solve the problem.  So, my question is: can I physically install these cards into my system, will they work, and if not on their own, is there anything I can do to make them work?

Thanks in advance.