Aww lucky, lucky you to get yourself a TAG.
The things you discribe seem perfectly normal to me and typical of a grey - except for the dislike of green, I've not heard that one before lol. If it were me I'd be inclined to keep the old cage until he is settled in his new surroundings and only then introduce the new cage, adding it to the room (as with the new toys) so he can comes to accept it "as part of the furniture" and that it's not some massive bird of prey that is going to swallow him Then after several weeks (possibly months, you will feel when the time is right) get rid of the old cage and begin using the new one. A similar colour sounds a good idea, I'd go for bigger but not too much bigger.
What is his name? Can't wait to hear of his homecoming and his progress from then onwards. Photos would be much appreciated. ;-)