Whichever card AMD has at the same price point as the GTX 970 significantly outperforms it in PC games, although I'm not certain about Dolphin.
Also, if you've not already bought this, I'd consider getting it somewhere else (and building it yourself if you've got more than four hours free before you need it) as you said you're paying £1100, and I priced up the parts you listed here (which doesn't include a case, but there's really not much need to spend more than £70 if you're not doing anything fancy like a pretty hard-pipe custom watercooling loop) at £870 at Scan. Even with a really nice case, that's £150 cheaper, which could go to more SSD space or GPU power.
Finally, that PSU isn't an especially high-quality one, so may, for example, not have the smoothest output, and therefore limit overclocking. While Corsair's expensive stuff is made by Seasonic, who are pretty much 'the best', their lower quality stuff isn't. With that said, I've got what some would describe as a fire hazard as a PSU, and it's been working for a few years without me experiencing any of the issues people say cheaper PSUs have, so this may be completely fine to ignore.
Also, if you've not already bought this, I'd consider getting it somewhere else (and building it yourself if you've got more than four hours free before you need it) as you said you're paying £1100, and I priced up the parts you listed here (which doesn't include a case, but there's really not much need to spend more than £70 if you're not doing anything fancy like a pretty hard-pipe custom watercooling loop) at £870 at Scan. Even with a really nice case, that's £150 cheaper, which could go to more SSD space or GPU power.
Finally, that PSU isn't an especially high-quality one, so may, for example, not have the smoothest output, and therefore limit overclocking. While Corsair's expensive stuff is made by Seasonic, who are pretty much 'the best', their lower quality stuff isn't. With that said, I've got what some would describe as a fire hazard as a PSU, and it's been working for a few years without me experiencing any of the issues people say cheaper PSUs have, so this may be completely fine to ignore.
OS: Windows 10 64 bit Professional
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56
CPU: AMD Ryzen 5900X
RAM: 16GB
GPU: Radeon Vega 56