I just found out about "custom laptops". Do you anything about them? For instance from Clevo and other brands. There's a forum post on Linus Tech Tips that has various manufacturers that sell custom laptops for much cheaper. I'll get back to this post tomorrow hopefully.
Sager/Clevo are popular laptops. I don't know how good they are. You can also check Eluktronics Mech-17 on Amazon if you want the lowest price.
If you want good budget laptop from well known brand, check Acer Helios 300 with 1660Ti, it's currently for 1200$. On turbo mode, it overclocks the GPU and allows the CPU to run at 56W, but that thing gets very loud. The Helios 300 is also undervolted on the CPU out of the box by 125mV, so you don't have to do it yourself (it seems you will have to undervolt all, or most laptops to keep the temps under 90°C). And even if you won't hit 90°C and more, you will still want to undervolt due to the power limit.
Lenovo Legion Y740 with 1660Ti may be a better choice if the price will be similar, but I haven't seen it on amazon yet. It has Gsync and doesn't get that loud, and from what I've seen it has better temperatures than most laptops out of the box.
If you want stronger laptops but still cheaper than others, I would check that Eluktronics.
MSI GE75 Raider looks good too, I also like Alienware Area-51m, but the Area-51m is expensive.
Lenovo Legion Y740 with 2070 MaxQ doesn't look bad either if you can find it for good price. It seems it ships with 90W version of the MaxQ and isn't far behind from the 2080 Max Q which is way more expensive. Normally I wouldn't recommend Max Q GPUs, only the Lenovo for a good price. Lenovo.com makes good sales if you are from USA. Recently they had 2080Max Q version on sale for 1550$
I wasn't really impressed by ASUS laptops at all.
Of course desktop gaming PC will be way way better than laptop (lower price, better performance, temperatures and other things), but if laptop is your only choice like in my situation, then I recommend checking these laptops.
Oh, and if you want a laptop for both gaming and professional work, Gigabyte Aero 15 looks great. It has slightly higher temps than most laptops and features Max Q GPUs, but it has great battery life and good ports with Thunderbolt 3, fast SD card reader etc. Lenovo has Thunderbolt 3 too I believe. Gigabyte also configured the CPU in it to throttle down at 90°C instead of normal 100°C. Not the best laptop for pure gaming, but if you want good portable laptop for work,gaming and high battery life, this seems to be a good laptop.
