Dell :: E1705 / Nvidia 7 Series / Upgrade / Cooling

Having geforce go 7900 gs 256 Mb (17 inch, 1920x1200) died after 2 years of using it, but played only moderately. I noticed sometimes GPU was over 80 C. No more warranty, so I plan on getting a replacement.

7900 gs is 20 Watt current consumption. There are cards like 7900 GTX, FX2500M tht have 45 Watt. So roughly we could expect twice as much heat made if replaced to a 45 Watt card. Am I right here? Now, even 20 Watt card (7900 GS) was overheating with only single heat pipe. 7900 GTX or FX2500 would have to have for sure 2 heat pipes, but since we have twice as much heat, do we have the same situation?

What is your experience with 45 Watt video cards in Inspiron E1705 / 9400 ? Do they overheat (and break) as often as 20 Watt and single pipe cards?

And second question - reliability of refurbished cards or "working pulls" How long can they last? I know it all depends, how the previous owner was using it, etc. When buying used card, what possibly was overheated more? 20 Watt single pipe or 45 Watt dual pipe (like the question above)
I would appreciate any oppinion and experiences from you.

In the future, I plan to better take care of cooling, remove dust more often, use AS5 paste, fan control, use dual pipe. Anything else can be done? Maybe going to 20 Watt with 2 pipes - would probably cool down system the best.