Given the limited overclocking headroom on both a 2700X (maybe 150W peak) and 2070 Super (maybe 250W peak), a quality 550W unit should be plenty adequate.
Rosewill Hive Series 550W Modular Gaming Power Supply, 80 PLUS Bronze Certified, Single +12V Rail, Intel 4th Gen CPU Ready, SLI & CrossFire Ready - HIVE-550S