OK. Got the right one now. Only one thing I can say about it. WOW!
That is way, way faster than what I used to use (an app called SMBSync2) and the choice of what to connect to looks to be about anything out there. Didn't take very long to setup a connection and I had to spend a few minutes trying to figure out what was wrong. Turned out nothing was wrong, it just worked so fast I didn't think it did anything. The folder in question (on my local NAS) had about 20,000 files and the sync was done in about 5 seconds.
I'm going to keep playing around as this might have a use in a number of situations.
Thanks!