Fan for t5 retrofit

[ecam]

I have a floating canopy that houses my radions. I will be adding 4 80w t5s to the tank. I want to run a fan to be able to cool the bulbs. Can u guys recommend a quiet fan that won't be too noisy on wood?

Also. Should I but the fan under the t5s. Or over the top of the ballast?

 

[ecam]

The top of the canopy. ( fixture was replaced with radions)