a moon watch would be a good pickup, snoopy moonwatches are even better, but for a daily wear, i would top it up and get a 5513, you could save a little more and go for a vintage milgauss - its underappreciated imo
Congrats on the dream-job for many of us promotion, now that really is a career milestone and a solid one. Maybe You could find a 16570 Explorer II for that budget otherwise I´d also top it up to 5.5 k and get a vintage 5513, GMT or Datejust, imo longterm pleasure and retains the value.
If You´re going for other brands a new Breitling SO Heritage Chrono or non-chrono are within budget as well as several Omegas http://www.jomashop.com/omega-watches.html
Normally I'd say Moonie hands down but given the reason for this buy there is only one option to celebrate such a milestone and that my friend is THE pilot's watch, a Breitling Navitimer. I'd go two tone on leather like this: