I would, like many other members of this community, consider what I need to fill the "immediatete" gap in my collection. Personally, I do own a 5100R and a 5059P.
You have mentioned that you think the case of 5059P is wrongly-proportioned. So it's been ruled out. You also said you prefer 3940 to 5140 because of the dial layout. For this, I share the same opinion. However, 5040's dial layout is another story, but of course the 5040G has to be the one with Breguet numerals (not railroad) and how about the color of the dial? You didn't mention if it is silver or the rarer black (like that of the 5041, as shown in my third pic).
Function-wise, if I don't have any perpetual calendar in my collection, I'd add a 5040 first, then later 5100. I have always had the weird thought that I must have a perpetual if I collect Patek. 5040 is a very good start coz it's value for money at the moment.
For daily wear, a 5040 is just as wearable as 3940. For size, 5040 might probably fit you as well because I guess you don't have a large wrist (since you mentioned you do mind the thickness of 5059 and 5100, and the big gold Hublot the Russian was wearing. And I can be quite sure, you can't take your eyes away when it's on your wrist, subtle though it is. And that's why I'm hunting for one myself.
So my suggestion is, if I were you, I would go for the 5040G. I would also put on a brown old-looking leather strap to go with it. Oh, and one last point, I could then save 10K Euro for my next purchase. ; )
This message has been edited by Hamster07 on 2012-09-05 01:52:48