Convert 6speed to auto? 7th gen

Wondering if there is a Toyota automatic that will work on my 2001 gts? I bought this thing used to drive to work and fell in love with it. I knew the snychros for 2 and 4 were failing when I got it. I am prepared to have the trans rebuilt but want to see what other options are out there. It seems this trans fails a lot. Was it just not up to the task or operator error that causes all the failures? I see the tc gets good mileage with the auto I do not want the 4 speed that was offered on the gts. I would just buy a used trans but with all the failures and people converting from auto to 6spd they are hard to come by. I drive 100 miles a day but I live for the 10-20 miles where I can redline 3rd.