Get a His IceQ3 Turbo X1800gto (gto not gto2). I've yet to hear someone say that they couldn't unlock it to Xl.
I have one and mine will run 16pipes @730/730. Thats good for ~10,000 in 3dmark05 which is near 1900xt territory.
And theirs no need to get a better cooler. The one that comes with it works extremely well and is almost unaudible.
And it only cost ~$200.