Audi gearbox transaxle query

[ade61]

i'd like to use an Audi transaxle (as fitted on A4 etc) on a light van conversion. It seems the best types are DCN, DHE & DWG, all with 4,55 final drive. But i need a taller first gear than the standard 3.5 (?). i need something like 4.2 ish for first. Anyone know if other gears are obtainable. (Also, anyone know the differences between the 3 types listed above).