LINK I use these which are listed at 1600 with 11 cas, but I bumped them up to 1866 with absolutely no increase to the already low stock voltage of 1.35. you can't get any lower profile. hard to find it though. glad I bought my second 8gb while I could.
I generally hear neutral opinions of them. I've never owned a Powercolor brand card myself. One of the main things I notice is that their warranty is below industry average for high-end cards. But I don't think I've ever owned a graphics card for more than 2 years anyway.