it's barely out, you're gona have to wait on that waterblock, it may never come since waterblocks are mainly for enthusiast who purchase enthusiast level cards (top end) those are the ones they usually make water blocks for. if anything you can try using a universal water block
Don't do it man. Instead of 4 r7 265s why not 1 r9 290? 4 r7 265s and 4 waterblocks would cost stupid amounts of money and you wouldn't see much benefit past 2 cards in crossfire.