Don't bother. Might as well message a TD and ask for the latest V6 Factory Big Bang in Gold. Comes with an Asian 7750 as every rep of the Big Bang has.
4100 is better, but this is the GEN-Movement. So there is no alternative to A7750 when you want to buy a Rep for less then 2k US$. Any dealer, who will you sell you this watch with a 4100 movement is a liar.