We've seen the 5177 a lot here and it is gorgeous (date aside), but I have no idea if they still have it in current production. Some of their other enamel work is also impressive, though I doubt it runs below 17k....
But in that "mid-tier" range I would most probably go for a Bulgari OF over any JLC or Breguet. Vacheron is obviously a superb brand, which if it has something within your friend's range should seriously be considered as well.... ;-)
A good and interesting problem to have!

Cheers.