This is always a very hard question to answer as it depends on how you use your software.

These are the system requirements for Civil 3D 2019:
https://knowledge.autodesk.com/support/civil-3d/learn-explore/caas/sfdcarticles/sfdcarticles/System-requirements-for-Autodesk-Civil-3D-2019.html 

Here are the BricsCAD system requirements:
https://www.bricsys.com/common/knowledge/topic.jsp?id=65

We recommend 16gb of RAM ( 32 would be great for future updates but RAM can be easily upgraded in the future on a desktop ). A solid state hard drive is good but if you have the data/drawing on the network then the benefits will be reduced, and the graphics card really depends on how much visualization work you do.  You may consider a Quatro or a good gaming card like a 1080 GTX.

Otherwise, if you are matching or exceeding the minimum system requirements of the CAD system you operate inside, you will typically meet all minimum requirements for Civil Site Design or Stringer.

Our staff typically opt for a high performance gaming laptop and they don't have any issues with performance of Civil Site Design/Stringer or Civil 3D/AutoCAD/BricsCAD.

With CPU more cores are good but the clock speed is what will give you more performance boost as Civil 3D, AutoCAD and BricsCAD only uses 1 core for most operations. Win 10 as the OS.