They are all very desirable watches. Personally I find 5146 a very interesting watch. I like its history, its shape, the depth of the sub-dials and the clean and very subtle texture of the enamel surface on the main dial.
Patek seems to be following a trend towards faster-beating, 4 Hz calibers with some of its new releases (5124, 5960, 5098 are the ones I have been following), so if your AD is sent a 5146 with a 4Hz movement I would say go for it as this watch is and does what a watch is supposed to be and do. My 5146 comes with a 324 caliber. I tried on a Breguet Marine Tourbillon as well during the purchase of my 5146; a stunning piece, but it is hefty and I would not wear it before my humble 5146. I find 5135 really too big for my wrist.
In the short time I have seriously entertained the purchase of one of these pieces I have noticed, as others have pointed out, that annual calendars for the moment seem to have escaped the attention of speculators, so you can get a lot of watch for a relatively modest amount of money, and even a small discount from your authorized dealer. I am sure you would have no problem selling yours, should fortunes change, regardless of which of those three you chose.
Finally, if this is your first really substantial watch I would have no hesitation to advice you to obtain it through an authorized dealer. Unless you really know the many potential pitfalls and how to avoid them, I would say e-bay and Patek are words that do not mix together too well.
I travelled a little distance with a fellow enthusiast and good friend in order to get this watch with this caliber. It was a great experience to see the precinct opened in front of me and to purchase it from a reliable and knowledgeable person who was not using underhand, money-pinching tactics, and who was just as passionate about these watches as we are.
Kind regards, and please let us know your choice.