engine/tranmission reccomendations

[Jmac05]

Howdy,
I er, my wife and I just bought a '72 Burb. It has a rebuilt
350, and a th350. My wife will be driving it when it's done. I would like to know what transmission I should get, if this thing
is going to be treated like an overgrown station wagon. I.E.,
lot's o'freeway driving, as well as around town. Not very much
towing, if any.
What re the differences between the
TH350, the TH400, and the 700r4?
Also, if you live in So Cal, and know of a quality body and paint man, I'd like to talk to him, as well as a good engine builder and
interior guy.
Since I am an LED guy, I will be woring on some ways to make
the interior lighting LED only. I will post pictures when I am done.