That Vantec should be fine for the northbridge, but I can't tell if it will fit on the southbridge under the graphics card. You'll have a better idea of whether or not it will fit.
Only trouble with that type of cooler is that the fans are often quite loud and high-pitched - as they're small, they have to spin fast to cool effectively.
I didn't check your specs properly, specifically your motherboard. Nvidia chipsets do run very hot, an Nvidia board was the reason I bought a load of chipset coolers (later sold the board because I didn't like the layout, and the chipset still ran very hot). You'll need to check compatibility before buying, from some images I've seen you may have some space restrictions around the chipset so you'll need to check whatever cooler you pick will fit properly.
It's difficult to tell, but do the coolers on the board connect with heatpipes? It looks like the southbridge, northbridge and VRM coolers are all connected, but I can't quite tell. If they are, it might be difficult to remove the heatsinks, so you'll need to check up on that before you buy anything.
