Give Dean at DRC Transmissions in Elk Grove Village a call at (847) 364-5523. Knows his stuff, has a trans dyno to test them before they leave the shop and is priced very fair. He rebuilt the AOD in my 3800# single digit street car.
Also BC Automotive near Indy is another well know 4R70W transmission builder.
Joe at CRE has a lot of knowledge on the AOD/AODE/4R70W. But I do not know anyone using him for transmissions. I also know there has been a lot of complaints about him in the last few months on CMC. 'might want to look into that.