My free hand is usually making obscene gestures at other drivers. Seattle traffic sucks as bad as So Cal. I need a manual shifter to keep my hand busy and keep me out of trouble.
As for an auto there are a lot of choices. A 700R4 would be a good one for no computer stuff. Or if you don't mind getting involved with computer controlls any of the current 4 speed or even the 6 speed auto would work. TCI has a retro fit 6 speed with paddle shift option available (no idea on cost though).
Twist Machine has a paddle shift system for many of the current autos. And I think they can also provide the entire trany and control system. Look there first.