Several companies make universal GPU only blocks but you need to check exactly which card you have, on some the GPU die sits a little below the surround, on some it sits flush and on others it sits a little proud of the surround, pop the current cooler off and examine the contact surface, if it's flat you won't have too many issues finding a universal block, if there's a raised square things will become more difficult.
Also bear in mind it is ESSENTIAL to cool the VRMs on these cards, the voltage regulators have no thermal cutout and will, literally, burn out if undercooled.
For a full coverage block you'll still need to remove the existing cooler so you can compare its contact points with those on the waterblocks, as has been said, there is several variations of the PCB and you need to get the correct block.
You'll also need a decent 240mm rad or a 280 if you want it quieter, so check your case will accept one and don't forget to add the 25mm fan thickness!