Revit uses core processors to create renderings. The more processors you have the faster the renderings. The graphics card does not help unless you use Vray for Revit or Enscape to create your renderings.
I recommend purchasing a PC with a threadripper processor with 16 cores minimum. A good graphics card is the RTX 2080ti. This graphics card has ray tracing hardware which will help with Vray and Enscape.
For a laptop I recommend buying a MSI GE75. It is has a 17 inch screen and has the RTX 2080 graphics card and includes 8 core processor.
For RAM memory I would go with 32Gb but 16Gb will also work.
For your hard drive, I recommend a 1T drive in RAID configuration to make it faster.
Video recording software such as Camtasia use 100% CPU so the more cores the better.
Hope this helps