Unless you have put a significant amount of money into other modifications, I would seriously recommend selling the automatic and buying the manual transmission version of the 2GNT. It's way easier than doing a swap.
2016 WRX STi Limited (current)2001 A4 1.8tqms (donated)1991 GVR4 #1933 (sold)old.dsmregistry.com/detail.php?carid=218 (dismantled)