Unfortunately, both of your links are broken so I can not be sure which Noctua you are referring to.
I would, however, assume you are considering the NH-U12P SE1366.

With your Antec 1200 series full tower, you should have no issues fitting either of these coolers (or any other really).
Xcpus did a review featuring both of these coolers not to long ago and they performed within a few C° of each other.
Overclocked and under load, the Noctua seemed to come out just ahead.
As they are both similarly priced and perform nearly the same, it really comes down to your personal choice on the aesthetics.

You can locate Xcpus review of the Noctua here:
and their review of the V8 here:

Please note that you will have to replace **** with
.com in the link for it to work.

Also, I would have to agree with theAnimal about the RAM.
Unless you are editing videos or doing other heavily memory dependent tasks, having more than 6Gb will give you no performance increase. Might as well save some cash here.