Hello Im thinking about purchasing a 2.8ghz 8 core mac pro from refurb ($2500CND). I have a few questions before I do this though Im not a graphics whore, nor will this system be used for games (I need raw number crunching power), but I will need 3+ monitors. along side the ATI 2600 XT that the system comes to, can I buy another ati 2600 xt from say bestbuy and use 4 monitors? Will any stock ATI 2600 xt do... or must I get a "mac special" vid card? Do I have to get special mac RAM to upgrade? What would you suggest I upgrade to. System Usage: I will be heavily using vmware fusion.