Don't confuse the Pure Rock with its larger Dark Rock brothers. The Pure Rock is on par with the Tx-3, and it's bigger brother, the hyper212 is on par with the h55/h60. Moving to a small AIO like the h60 will get you a drop of @ 5-6°C at best under load and 1-2°C at idle. Honestly not worth the effort.
Cheapest solution is to play with your fan curves, costs nothing but time. If your gpu is raising cpu temps, you aren't dumping enough heat out of the case. Speed up your intake/exhaust fans some extra when the gpu is pushed. Add a couple of fans, if that's what it takes, or swap to 140mm if possible. If all that's not an option, then move to a larger cooler like the Dark Rock Pro or Noctua NH-D14, Phanteks PH-TCP12, Corsair H80i, Nzxt Kraken x41, Cryorig H5,etc.
A move to any cooler that's only a small step up from what you have now is more a lateral move than an upgrade. When it comes to the cpu, there's no such thing as over-cooling.