Unless you are water cooling, I don't think the Cosmos is the best choice. Those two GPUs are going to put out a ton of heat and you will want the best cooled case you can get. If it's a question of style go with a Silverstone:
That was a single card, and the Cosmos S, but yes it was OK. There are other considerations than the GPU temp however, such as ambient case temp and CPU temp.
I do like the Cosmos and simply said it would not be the BEST choice. 2 cards will dump probably 150% the heat of one card into the case, and having a good stream of air passing both cards on it's way out of the case should make a nice difference.
I like my G5 mouse because it's weighted to my preference, mostly. The precision is probably not something of which an old man makes good use. It has however been INCREDIBLY long-lived. The finish has been worn off and still it functions perfectly.