Vest Button Stance and No. of Button

That is not appropriate. The waistcoat should have 5 or 6 buttons, with 6 being the most traditional. Both would have about the same button stance.

You mean a real waistcoat as opposed to a vest?

 

The reason I started to consider this is because I'm getting the suit from indochino, and they give the option of 3 buttons on the vest. However I thought if there's 3 buttons they shouldn't be the same distance apart as 5 buttons, thus the 3 buttons would look better lower, and they also happen to offer a rounded gorge sorta like the one in the previous post.

The fact that I want the suit as single button makes me think the vest would look better with the low button stance cuz the one button jacket would probly have a slightly lower button stance as well.