Buddakahn or Tao have good bar scenes for before and after dinner. The food at both is average. Many steakhouses such as Wolfgangs, Keens, Sparks.....have excellent food but not much of a bar scene. The bar scene at Angelo and Maxies on Park is excellent although the steaks are decent but not the level of the previously mentioned.
Lots of good after dinner spots will not be thrilled to let in a group of 10 guys with no women especially after 10PM.
You can also go to ONO in the garden of the Gansevort hotel, eat some good sushi and then stay for the party scene however it is a little younger than you guys.
For dinner I would say Vento, Buddha Bar, STK are good options and then there are clubs actually located within these restaurants. Vento has Level V, Buddha Bar turns into a club and STK has Tenjune which is right below the restaurant, however it is difficult to get into sometimes.