If you really want to go after market with a Quality cooler then I suggest a Zalman VF900 and they can cool most cards out there. I have seen people put them on x1900xt and 4870. Both those cards easily dump around 120-130w. I got one on my BFG 9800gt (standard w/ 55nm core) and it does the job nicely with load temps below 60c. I had a cooling failure though when the power to the fan became disconnected which was my fault the card heated up to 121c and still run without issue. I quickly shut down the rig and fixed the problem. The lower card is a much older version and it uses a vf1000. Both are in sli. As for fan modding your card the stock cooler has got to me worth while for the mod or it wont work. A lot of those cards had fins that were open at the top while many single slot coolers are not. The arctic cooler will do the job though and with much less noise.