Abobe Air for developing business tabblet applications ?

Hello.

I'm new in this topic.

At this moment our company have a business tabblet application that is wirtten in C# and works on a windows device (Panasonic touchbook).

Now we are looking to renew the devices and also the software.

Our goal is develop software that can works on Android, iOS & Windows.

The application must work with data on a local database and sync ever hour with a server.

The is also communication with a WCF service for some actions.

Is Abobe AIR a good product for developing big business applications or is it more for developing games ?

What is the difference with Phonegap. Is Adobe AIR also making a website and compile it to an app like phonegap ?

We want that the users not have the feeling working on a website but have the look and feel of a native app on Android, iOS, Windows

Thanks for your advice to help making our choice

Nico