Are you planning to upgrade it? If not, $1000 won't likely give you satisfactory performance unless you only use SD media.
...well, between $1000 and $2000 you will find some very capable laptops for PPro, however, they MUST be plugged in while editing because on battery they will "throttle" and choke. I use an Asus gaming latop which is now 2 years old...the G750JW. It handles multiple 1080p tracks with effects pretty easily,but, 4K is much more challenging because of the only 2GB of video memory NVidia 765m GPU. I self-upgraded the system memory to 24 GB and put two quality SATA III SSDs in it to greatly improve performance over the supplied 1TB spinning HDD and 8 GB of original system memory. The i7 4700HQ CPU is close in performance to today's newest 4 core i7 laptop- CPUs.
Look for an Asus which you can upgrade yourself,or, which already has good components. You want at least 32 GB of system memory, 16GB is just not enough for the current capability of PPro and today's more difficult codecs. You also want an Nvidia mobile GPU which is a 9xx series with at least 4,or, even 6 GB of video memory.
The newest laptops are starting to come with PCI SSD storage.....which is HUGE for the demands of video editing. How those drives are deployed is crucial, however. For video editing, the speed of the boot drive is not that important because the OS and programs become "memory resident" once loaded. The tremendous speed of PCI SSDs is needed for the video source files, project files, previews, and exports. The "media cache" and "cache" files can go anywhere without affecting performance. So, that means if you find a laptop that has an empty 2.5" drive bay, you can put your own SSD in there to become the "boot drive" while using any PCI SSDs for all the other files I mentioned to provide fastest performance. If a new laptop has more than one PCI SSD in a RAID 0, you may just have everything on it with no hindrance to performance. Even with just ONE PCI SSD and all files on it may also run fine and even better than separate conventional SSDs. So, LOOK for a laptop with PCI SSDs !
I saw this today, my own laptop was bought refurbished from this site and arrived in like new condition with the plastic still on it. I have had no problems with mine, This laptop has 2 separate 2,5 inch HDD bays whee you can place quality SSDs. It also allows a RAID 0 betwenn the 2 SSDs for fastest drive performance of about 1 GB/sec read and write....all files could go on that.