[thxbb12]

Preferences are: lightweight, mirrorless system.  Thanks for your opinions.

If you value lightweight (and presumably size as well) then micro 4/3 makes probably more sense than any other mirrorless system.
I'd recommend a Panasonic GX9 body as it can be had for nothing these days while still providing excellent IQ in a lightweight and small package.
Here are some options shown in the image below:



From left to right (prices in Swiss francs from http://toppreise.ch):

• Canon RP + Canon RF 24-105 f4. Weight: 1185g (485+700). Cost 2088 CHF (1080+1008)
  
• Panasonic GX9 + Olympus 12-100 f4 (FF equivalent 24-200). Weight: 968g (407+561). Cost 1482 CHF (500+982)
  
• Panasonic GX9 + Panasonic 12-60 f2.8-4 (FF equivalent 24-120). Weight: 727g (407+320). Cost 1246 CHF (500+746)
  
• Panasonic GX9 + Panasonic 12-60 f3.5-5.6 (FF equivalent 24-120). Weight: 617g (407+210). Cost 875 CHF (500+375)
  
• Panasonic GX9 + Panasonic 12-32 f3.5-5.6 (FF equivalent 24-64). Weight: 477g (407+70). Cost 500 CHF
  

Depending on your needs you can go from super tiny/light to heavier/larger while being very versatile.
A good compromise is probably the GX9 + Panasonic 12-60 f2.8-4.