6 Speed Transaxles

Can anyone advise me which of the Audi 6 Speed Transaxles have the highest power / torque ratings as I am looking to use one in a special I am planning.
Thanks in advance.

I think I have determined that what I need is an 01X Gearbox, however can anyone advise me on what the numbers and letters are following the 01X, I suspect it is something to do with the gear ratios fitted but not sure how to interpret them as for the 3 letters that is a complete mystery.
By the way I do not intend fitting it to an Audi but a mid engined sports car.

OK got my 01X transaxle I now need to uprate it with ideally straight cut gears and stronger shafts,
Anyone got any ideas?

Hmm I was told that it would happily handle an american V8 with sensible driving, not sure how well it will cope with the 500+ bhp of the BMW V10 though?