This 1000W 80+ Platinum Thermaltake Toughpower SFX PSU is $175 on Amazon USA
For those building an SFF PC with lots of grunt.
For whatever reason, components for smaller form factor PCs, such as lower profile GPUs and properly-fitting power supplies can cost a bit more than their more standard contemporaries. With this in mind though, there are discounts to be had if you know where to look - this new Thermaltake Toughpower PSU is fully modular, 80+ Platinum efficiency rated, and offers 1000W of power in a proper SFX form factor, and it's got a handy price cut from Amazon USA.
The big thing here is that this is a proper SFX PSU which should fit well into your SFF build, if you need 1000W of power of course, while being ATX 3.1 compliant also means you should have no trouble using it with the most modern components, as it comes with a dedicated connector for the notorious 12VHPWR cable for modern Nvidia GPUs. This Toughpower model is also fully modular, meaning you can save any unneeded cable clutter, which is important when you've got less space internally to work with. In addition, its 80+ Platinum efficiency rating is excellent for providing peace of mind, and while this model hasn't been through the folks at Cultists' labs yet, the previou model was A-Tier rated.
1000W of power is also enough for powering even some of the beefiest of systems. It's above the recommended wattage for most 'standard' RTX 4090 offerings, apart from some overclocked models which have a 1000W minimum, while everything underneath that from both Nvidia and AMD will be more than adequate. For the RX 7900 XTX, the recommendation is a bare minimum of 750W, so 1000W gives you more than enough headroom.
If you're in the market for a beefy, efficient PSU to slot into your small form factor PC, look no further than this Amazon deal on a Thermaltake 1000W model.