Have a look at Stowa Watches. Their Fliegler is simple and stunning (and niche too!) and will leave you enough change for a pretty good full suspension bike.
Its a good job you are getting married next year as the Stowa waiting list is around 3 to 6 months.
Something simple and classy
id try and pick up a
For £3k you could pick up a nice pre owned Panerai Luminor Marina from a reputable supplier - I can recommend Watchfinder.co.uk, I have just purchased a pre-owned Bell and Ross and they were fantastic to deal with.