New Client-Lunch Meeting on a Monday?
I am not a fan of Bar Americain though there are many Hounds who are. Aside from my poor experience with the food, I don't think the atmospherics are right for this kind of meeting.
I would suggest the following:
The Modern, in MoMA, on 53d, b/t 5th & 6th - http://www.themodernnyc.com
Alto, on 53rd, B/t 5th & Madison - http://www.altorestaurant.com
Aquavit, on 55th, b/t Madison & Park - http://www.aquavit.org