Total Commander

1) Replace/duplicate right-click menu with icon toolbar (because right-click menu seems oversaturated);
2) Add the following commands to this menu:

Save left list
Save right list

and/or

Copy left list to clipboard
Copy right list to clipboard

Add the following commands

additional to Vochomurka s sugesstions:

only if one row is marked:
open right
open left
open right and left

if you want to compare the files and you need a program to look at them and decide:what was the right version i want to store?

or:
show one file in the left table and the other in the right table
(leave syncronisation dialog)

CEUM