Check your case documentation - What sort of radiator mounting will it support?
Thje NZXT product you listed is only an adapter that will allow you to use a Closed Loop/All-In-One cooler on your GPU, I would not recommend this.
From what I can see in the picture you do not have many, if any, radiator mounting options. The top fan looks like a non standard design or perhaps 200mm or above. That's not suitable for a rad.
Front is hard to see, but unless the HDD cage is removable/moveable it's going to limit your options. On the rear you have a single space for a 120/140mm depending on what size it is.
The case does not look the most ideal for a custom loop and even an Closed Loop/AIO cooler will be limited to a single 120/140mm rad.
In short, I think you either need to stick with air cooling and go with an after market cooler on the GPU or change cases to support a custom loop. Your other option is an external radiator but I'm not a fan of that either. Outside of Closed Loops/AIOs there is nothing really 'budget' about Water Cooling. Quite frankly 'budget' Water Cooling is just not worth it, do it properly or not at all.
We have a dedicated Water Cooling section (link below). Pop in, have a read around, look at some builds and do some research. Get a feel for what you want to do.
http://forums.overclockers.co.uk/forumdisplay.php?f=133
