Depends what you like.
The 4 speed auto if your lazy (my opinion). They are ok, i have driven a few and go very well. They have a reasonably short first gear which is a lot of fun. You can also get an edit which apparently makes the auto even more appealing with revised shift patterns etc.
The T56 if you enjoy "driving" a car. But they are a big box and don't expect smooth gear changes. Don't expect it to be as easy to operate as your mums 4 banger box. They are designed to cope with some big torgue figures and accordingly need big lumbering internals.
Personally i got a manual and would not choose otherwise. Always had manuals in the past and i find them rar superior over the auto. Its like comparing chalk to cheese.
Take them both for a soin and see how you go.
VX SS - Twin 2.5 cat back - MAFLESS Tune - MCAI