I can tell you from personal experience those damned Intel fans are very noisy at 12V. If you drive them at 6 or 7V you'd probably be OK. How would you attach the COB's?
Personally, I would use one with copper base.
http://www.newegg.com/Product/Product.aspx?Item=N82E16835200014
These are the ones I used in the Battlestar Gangactica. Silent even at 12v and runs nice and cool with Cree CXA3070s. 2day prime on amazon. Great buy!
Yes that Arctic fan is better, it has fluid dynamic bearings.
Personally, I would use one with copper base.
http://www.newegg.com/Product/Product.aspx?Item=N82E16835200014
Agree, and as mentioned the price is right.
These are very nice. After looking over the Cree CXA LED Design Guide I am more convinced that putting work and care into the thermal interface is well worth it