Dude.. post on the ME/MINE/MODS section of the site FIRST or the mods will have their way with you and your girlfriend.
Re your question, I believe you got the 3speed auto? if so I would suggest you don't keep that one. I think the 4speed is better if you wanted to do this swap.
The 16V 4AGE never came in automatic in north america and I'm not sure if it came auto in Japan or Europe. However the 20V 4AGE and I think some 4AGZE's came in auto in Japan. You could do this swap if you can find a motor with the transmission, or you could use this transmission to do a 4AGE swap since the 16V and 20V transmissions are compatible.