First of all, your motherboard would need at least 2 PCIe x16 slots, second running at least at x8.
Using 2 different cards like those has no effect, aside from the fact that you could connect more monitors to PC then if you had one card. If you use 2 cards that are same model AND they are SLI/Crossfire capable, they will work together, giving you somewhat better performance then single card - but that requires motherboard SLI/Crossfire capable.