What are some fans that I could use fora retrofit that are very quiet and efficient?

[John Hartford]

I am in the process of planning a retrofit for my 210, and was wondering what fans are quiet but yet efficient. What are some of the fans that you have used?

 

[nait002]

I also use 2-4" Vantech Stealth fans and I have them mounted to blow under the Mh's. They are very quiet and I got them from fry's outpost.com. They are 12 volt so I bought a converter from Radio Shack. Real easy setup.