YN560EX review , but
I spent some time digging around because I might be picking up another speedlight and wanted to check out non-Canon alternatives. It looks like HSS is pretty rare on the clones. I did find the Nissan Di866 with HSS, but it's over twice the price YungNuo. The YN568EX might be your lowest cost option and it's got a pretty good reputation. Meike doesn't seem to make any speedlights with HSS at all.