Blancpain or Zenith ?

[acarriles]

Here's my question: I have a chance to trade my SS/18K Cartier Santos at a good value, but only if I get a higher priced watch at the same time. I don't use the Cartier any more, plus it is Quartz, and I prefer to have only mechanical watches for my collection.

Here are the options:

a) Blancpain Leman Chronograph. It is in mint condition, but has no box or papers. I can have it for $4800.00

b) Zenith Chronomaster Open. Mint condition, comes with box and papers. Also $4800.00

c) Finally, Zenith Grande Class Reserve de Marche. New, with box and papers. $3600.00

I am getting roughly $1950 for my Cartier.

Any opinions will be highly appreciated.

P.S. The order of the pictures is Z-Chrono, Z-Grande, Blancpain.