I got an ITX build so I got a Silverstone SX1000 on order. This will cover my current build and any future ITX builds.I recently discoved this was my issue with random power off's, Seasonic Focus PSU's don't handle the power jumps from the RTX3 series cards, however after some digging I'm reluctant to go for another Seasonic as they're washing their hands of the fact their suipposed top end PSU's rated at 850W+ are cutting out with spikes to around 600W! Their advice to turn off motherboard OPC is a joke. After some research, I'm currenty leaning towards the Corsair HX1000 units as they seem a decent all-rounder with solid reviews.
My 650W PSU is from Seasonic.