Trying to understand display specs of macbook pro
1.Will they work with macbook pro as I cannot find 1920x1080 in the supported resolutions above?

Yes,they would work just fine.But only with resolution of 1920*1080 or below.

2.Referring to "Up to two displays with 5120-by-2880" - does it mean each monitor has 5120x2880 resolution? 

You could output 5120*2880,but the monitor may not support it.

3.What would be a middle-of-the-road recommended resolution to buy? 

To use an external display from a MacBook Pro ,I would only recommend displays with a resolution of 4K or 5K.

One thing you have to know about MacBook and external display is the output is blurry due to the font used by OS X,and the only solution to this is high resolution in much smaller display, or HiDPI.