3 monitors with Dell T5400 & Quado FX 570

[slowbiznatch]

Sorry to sound a little out-of-the-loop, but I haven't been in the video card game for quite a while. I'm attempting to setup triple monitors (all DVI, if possible) on my Dell T5400 workstation. It currently has a Quadro FX 570 installed and it has one empty x16 PCIe slot. What do I need to throw in there to add an additional monitor? Can any NVidia card work or do I need to get another FX 570?