HD efficient cooling

[mastrmndv2]

I plan on doing a slight bit of modding to my TJ07 soon and I'm looking at mounting this

http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=257&products_id=974

at the bottom of the TJ07 case in the space provided for an additional power supply. My worry here is that the HD's might be to close together and the fan would not provide adequate cooling. One drive runs around 39 C and the other one is at 27C. Not the hottest drives in the world but I plan on upgrading to possibly to 74gb Raptors in the near future and I'm just wondering if this will provide sufficient air flow and cooling through the HD's. Any input would be most appreciated.


Also is watercooling really that much more beneficial over simple air cooling for gaming and everyday use?