Call me crazy, but you should begin collecting miles/points first and ask questions later. Since both AA (One World) and UA (Star) offer tremendous possibilities out of NYC, stop thinking one or another and do both. Citi AA cards have 50K bonus for personal and 40K for biz and can be churned right now (it won't probably last long). UA has 50K bonus for both personal and biz with a trick that's easy for many people. Don't forget the US Air 35K bonus; US Air is in bed with Star now but will migrate to One World soon. Apply for best Chase Ultimate Rewards cards (CSP, Ink Bold and Ink Plus), and you'll get 140K Ultimate Rewards points transferable to United among other partners. Get these for starters and you are set for a pretty long time.

However, let me tell you all right away: being in NYC, it's becoming harder and harder to meet spend requirements. So if you despise paying for the privilege of using plastic make sure you can handle the spend.