00' Autoamic Performance Tranny Help

Does any one know of a performance transmission for a automatic 00' V6? ive spent about 5hrs. looking around and still nothing but GT tranys. Seems like they only sell parts but not the whole transmission. Mine is done for and since im gona get another one mides well get a performance since i will be at the track. Any help anyone?

Since i installed the 8.8 rear end the trany has since started bogging down. I can feel the shift points reving higher (in the 600 sometimes) so i was wondering if thats normal or its just me. And yes for harder shifts as well as im planning on getting the M112 supercharger very soon.