ok so your post is a little confusing to read...
Android isnt the ipad.
Android is the OS run on the galaxy tab or the Xoom.
Ipad runs the Apple OS.
all have the option for 3G via a simcard placed in the unit, you cant plug a mobile broadband dongle into any of them.
Personally id get a netbook, but only you can answer which one will suit your needs better, at the end of the day a tablet is limited and cant do more than just being a tablet where as a netbook is just a pc with a small screen.