Use 2x corsair h55 aio's with 2x nzxt g-10 bracket adapters.
For a single rad, pull one apart, clip the pumps in line, salvaging the coolant first.
Could also use h90's if you wanted a 140mm rad and higher capacity pumps. It's the asetek pump that's important, as that's what is designed to fit the g-10 bracket.
All depends on budget, skills, determination etc. Alternatively, you could maybe get ahold of the stock r9 295x2 liquid cooler, which would be the ideal candidate, maybe need to extend the pipe between the 2x pumps.