LexusIQ

Hey can anyone help me with making a good decision on choosing an automatic transmission that can best hold 500+Hp in a Sc 300 1995 Lexus 2JZGE with a turbo at 5psi ...on the dyno creates a maximum of 350 hp to the rwdhp with anew install of a Diff TT Supra LSD 3.7...should I go with 1jzgte tranny with auto shift kit, or TH400 tranny with bell housing and adapter???
What do you think is best all around, with the install and long run durability?