You can get a Surface RT fairly cheap these days. Has MS Office, and "inks" well with an Adonit Jot Pro stylus. With keyboard, s/b way less than $400. And when you have time to game, it works with a USB or wireless Xbox controller out of the box. I play Halo: Spartan Assault and Asphalt 7: Heat on mine.

HDMI out to a big screen, and you've got a full on game console!
And just my opinion, but I'd stick with a 10" tablet over a 7" or 8" for your needs. I love my Nexus 7, but I find it easier to be productive on a 10" tablet. YMMV.