Short answer it will run great. Max out all the RAM you can afford, it can’t be upgraded later, and do get a i7 processor if you plan to keep it for some years,
Mine is:
iMac 27 Late 2013, Intel Core i7, 3,5 GHz, 32 GB RAM, NVIDIA GTX 780M – 4GB, Fusion Drive. (and I haven’t had a glitch in performance at all)