I need a good cooler that is really quiet, but still cooling efficient. One person told me to buy a Xigmatek HDT-S1283 and replace the fan with something quieter. I have also read that the Scythe SCZP-1000 is extremely quiet and still cooling efficient.
Any recommendations?

Noctua NH-U12P, Swiss know how

The Xigmatek is a good choice,

Thermalright Ultra 120 is really quiet with a good fan (artic or Scythe fan)

Although with both of these you will need a big case.

xigmatek s1283 with a slow speed scythe (volt modded or stock low speed) or a yate loon fan if you can find them.

artic cooling freezer 7 pro 92mm. if its good enough for Lyod Case of ExtremeTech.com. its quiet, efficient, easy to install. he uses it to overclock. also look at the newegg reviews.

+99999 for yateloon fans. i have one in my antec neohe 430watt psu. so silent, good airflow for 800mm.

dont forget cheap! yate loons are about 1/3 the price of all other competing fans.

yate loons are hard to find.

how do i get my signature to work? i dont see it. its supposed to be my current pc specs.

I would go with the Scythe Ninja+. If you can drop about $70 for a HSF, then the all copper version of the Scythe Ninja+ would be my choice.