Places to buy SMPS?

I have tried a couple of these from eBay. They claim 500w, I think that’s a maximum and more like 350-400w RMS IMO.

500W Amplifier Dual-voltage Audio Amp Switching Power Supply Board PSU 100V-240V

Also look on the Vendor Bazaar of this Forum for “Cresnet” his website is in his Bio. Haven’t used them but a lot of positive reviews in his SMPS Vendor thread