With that there 9700K CPU boosted to the end of the Galaxy, it would be difficult to recommend a decent GPU for the application you wish to use it for. Anyway, with the minimum GPU specifications listed below you may be able to play games with a mix of low, medium, high, and ultra settings. I hope this helps. I could be wrong!
Minimum GPU Memory size (VRAM): 4GB
Minimum GPU CUDA Cores: 2048
Minimum GPU Memory Type: DDR5
Minimum GPU Memory Interface width: 256 bit
Minimum GPU Bandwidth GB/sec: ?
Minimum GPU Base Clock speed: ?
Minimum GPU Boost Clock Speed: ?