Well, You could build an AOD to hold that power - but you won't get 4th gear. 4th is WEAK and should never be used as a solid gear for motivation with exception of hiway over 45mph and crusing. The OD band is just not tough enough. There are some folks trying to make AOD/E/4R's to have a super strong 4th but it requires some mods like better bands and HUGE holding servo area. BUT IMHO I would not move to an AOD because you need another gear. YOu need to change the rear out if that is the case.
As for the swap info, I have never gone from c6 to aod so I can't help y ou rigth now with that. As for size - c6 is MONSTER compared to aod and the mounts are different and the flywheel. You will also have to use a TB or carb setup to run the TV cable on the AOD (no vaccum)
I will add my .02 here and say if you want a reliable/strong tranny and still want an OD I would consider the 4R70W with the Baumann TCS stand alone electronic controler. The FACTORY 4.2 V6 4R70W is rated at 400hp, with a few mods it will hold 1000 if you want it too. Check out: