You really don't. All the companies use pretty proprietary PSUs and theres really not much review/testing done on them.
Honestly buy/build a high end desktop, then buy a cheap low end every day laptop for work and general use. Gaming laptops are expensive for the price to performance ratio, noisy because of small coolers and fans, and with the way CPUs and GPUs are putting out heat these days typically all suffer from thermal throttling especially the more powerful ones.
If you need to game on the go like lan parties or traveling you can build small ITX gaming builds which would still be cheaper and let you have better performance. All you would need is a small monitor.