My information shows a 6 speed 01E Quattro was available with the 4.2ltr. V8. At first glance, I do not see a listing for a front drive only 01E gearbox on the 4.2ltr. A8, however the bellhousing's are the same. There ought to be a number of Audi performace shops on your side of the pond that could assist you with fit-up issues. AFAIK, Audi employed the use of various thicknesses of sandwich plates between the motor and gearbox bellhousing for specific motor/gearbox combinations, so some attention to that may be necessary. Given the correct sandwich plate, I suspect the standard 4.2ltr. clutch and flywheel assembly should fit the front drive 01E gearbox. If you wish to not use the dual mass flywheel, those Audi performance shops ought to have a source for some performance flywheels (probably aluminum). Good luck.
Andy