Help buying: GMT-II 18k gold pre-owned

[cl600599]

Hi,

I am looking to purchase a solid 18k gold GMT Master 2. It has to be pre-owned because I do not want to spend $33k+ on a brand new one.

I need help choosing the year. The reason is, this model has used two movements since its production start: 3185 and 3186. I did some research and saw that the movement change occurred in late 2007(late Z-series and the M-series).

Is the 3186 worth spending more money on?

Is Sant Blanc in Branson, MO a good place to buy this watch? They look like my #1 choice to buy as of right now.

Any reply would be greatly appreciated by me.

Thank you

-Kyle