Got a MBA13, need some help

Hey Apple Core,

I just got a MBA13" and I need some help. I'm a heavy Google accounts user (and my account for College is a Google one too), so I need suggestions on which apps are best at replacing the stock MBA apps. For example, Sparrow used to be excellent for Gmail, etc etc.

Gmail, Calendar, & Hangouts are the most important ones for me and I would love it if they synced with Notification Center, got push emails, etc. I received the back-to-school $100 gift card, so I don't mind paying for apps either.

Thanks in advance,