cool, I gotta couple of links for ya. the first one is a 120mm DC computer case fan. I'm currently using one of these, works great, also very quiet. all you need to hook it up is an old ac adapter.

Thermaltake Silent CAT 120mm Case Fan - White A2329 at TigerDirect.com

the second one is an ebay store. when I upgrade I might go with these guys. (p.s. they have crazy deals on lights too.)

eBay Store ΓΆβ?¬β?? High Tech Garden Supply: Search results for.

and here's another site I came across, I've not dealt with these guys but thought they had some good deals.

Suncourt 4 Inch In-line Duct Booster Fan w/powercord - Businesslights.com

hope this helps.:thumbsup: