I recommend reading the configuration guide on the Blackmagic support page. Depending on what you wish to use Resolve for you will need thunderbolt to run outboard I/O and external GPU to get performance and accurate monitoring for grading.
The GPU and Blackmagic I/O devices will eat most of your budget before you buy the laptop unfortunately. If you are not using it to grade, just edit, then you might be OK with editing on a laptop but that is codec dependent. Same as all NLEs
If you get a powerful enough laptop you don't need an external GPU. At least right away. I would probably buy a beefy gaming computer. I've had a few MSIs and they've been great. They also have slimmer "stealth" models if you need to lug it around.