why would he regret going to a 6 spd? . if he plans on doing road racing or auto x then the 6 spd would be better suited since he would have more use out of the gear sets.
Why don't you get a shift kit like TransGo, It really wakes up your transmission, I installed it myself when I had the 4R70W and it really made a difference and my old ride a lot more enjoyable and faster. Research for it and you will probably like it, besides it is a much cheaper alternative (it cost around $100, and is easy to install as long as you are carefull).
Right now I have a 02 GT manual, but I'm thinking about going for a 06 GT auto and then install a Shift kit, that would be a sweet ride.
I would do this if I had a automatic just get a shift kit because why swap
trannsmissions when you don't have to.A Trans Go shift kit would help
your shifts become alot crisper and faster.You would only benefit from
installing a shift kit.Just an idea!