I see you have a bestbuy canada link, have you tried to look at Memory Express and Canada Computers yet (and newegg canada for online)? I use an EVGA 1200 P2 currently, runs well and boots quietly which is always nice. I believe Seasonic and Corsair also make really good quality power supplies which can be found around the 1200W+ range also.
Are you sure the issue you're having is with the PSU though? They very rarely fail and 1000 watts is definitely more than you need, most high quality power supplies come with a 5-10 year warranty even. I believe the 2700x only allows for up to 20 usable PCIe lanes (4 reserved) so maybe there are some issues going on there which you can look into. I don't believe a 2070 Super is able to fully saturate a x8 link (or if so, not by much), does Ryzen/B450 chipset allow you to allocate lanes? I haven't checked in a while but I think m.2 drives will take x4 each and Ryzen is relatively new so maybe you're running into some instability from that? Just a guess, but it is worth trying out before you go spend money on a 1200W platinum rated PSU as your system probably could run fine on even a 650-750W without risk depending on your processor overclocking.
I used to use a 750W power supply and had no problems with my similar though much older system.