Hi Bill,
If you can't get into Ko, you should try Momofuku Ssam. Also, try shooting for an early lunch at Ko on a weekend-- sometimes they have spaces available.
There aren't that many modernist options in NYC. wd~50 is obviously a must. Another place that uses modernist techniques is Vandaag in the East Village (although they recently lost their head chef).
For other categories, there are endless debates on these subjects and I recommend that you check out egullet or chowhound.
Happy to answer any questions.
Andrew
