*cough* A GF4 MX440? Maybe 8w TOPS? Umm, yeah.
But I don't know that it'll help. If the GF isn't OCed at all, then your FSB is up too high for your vid cards comfort (although I don't really know). Try a different card, or put a huge sink/fan on yours/ try ram sinks.
Seriously, though, just cooling your MX isn't really very common/ nessiary. Nor is cooling a cele. But if you were to, by far, yes, I'd be suprised if you needed a rad at all for just an MX series card. Occasionally spiting at the card would cool it enough.
I don't mean to put you off WCing, though, if you havn't already on another system (which it sounds very much so like you have); its great, but I don't think it's do any good in your system.
Cheers