If you like complications, then I'd opt for the PAM289. It's got an in-house movement, 8 days power reserve, GMT, and date.
The PAM140 is just ETA movement with date.
If you like clean and simple, then the 140 would be the obvious choice. The carbon fiber dial is simply awesome with the applied polished hour markers.
Please let us know which one you decide to get!
Cheers,
Anthony

PAM289 - pic from Panerai website
PAM140 - picture by Chis H