What Audi transaxle for RS4 motor

Hi all,
Just doing a bit of research, I am looking at making a mid-engined spaceframe chassis replica, not a GT40 though so I hope you don`t mind me asking here on this forum.
Audi RS4 V6 twin turb motor, I am aware that the AWD box is a non starter (or requires an awfull lot of work to use) so am asking what are my options? Hoping for around 400-500bhp with a dollop of torque from the "Donk" What Audi box can I use as a transaxle? I see from all the various posts there are many types available, different internals and final drives.
Or is it going to be a case of shelling out and getting a Hewland/Quiafe box to suit.
I see some of you are putting various V8`s on Audi boxes, so thought I would ask here.

It shouldn't be difficult to find a front drive 01E gearbox in the UK (that's where I got mine); it will bolt right up.