I think you need to be the guinea pig and find the perfect fan for the CV!
Here is a good resource I found: http://www.quietpc.com/120mmfans
They seem to based out of the UK, but if you find a fan that you want to use, you should easily be able to find and buy it from a US distributor. I wouldn't be surprised if newegg had a lot of these fans.
While I only had my CV5000 for a short time, I did push it hard and it never got remotely warm to the touch. With that said, even if you get a fan with a lower CFM (which will most likely be the case if you want to go quieter) you should not have an issue with your amp over heating.
Your amp is in a home environment and is not going to be subjected to heavy duty abuse (concerts, touring, etc...) that pro amps are designed for.