Stripwear wants to display text and graphs. Both solutions presented in this thread will more than suffice for this need.
Hence... The question comes down to how much money he wants to spend in addition to the computer and VGA-to-Ethernet converter. He can spend $100 for a standard PCI video card (with dual video ports). Or, he can spend $500 for the professional Quadro/Firemv 3D video cards. Only he can answer that.
If money is not an object, go for the better card.