Why would they make a intel or nvidia version? Those are two different companies that are actually competitors of each other. Intel develops it's own graphics hardware and desktop platforms as well as cpus. Nvidia develops gpus and desktop platforms. ATI/AMD are the same company... they offer...
There is no difference between any of the sniper models. Just paint. The stock sniper has an all black exterior and silver interior. The sniper black edition is all black. The sniper amd/ati dragon edition is just the sniper case with a custom amd/ati clear side panel window. The only difference...
Cooler Master's products beat antec's any day of the week. Over the past 1-2 years Cooler Master has released "Black Versions" of their cases. Stacker/Cosmos/Sniper etc.