i actually like automatics much better than manuals ( just my opinion) as far as an automatic turbo... just look at mr. Tigers car

you can turbo an automatic but if you plan on running a lot of power through the engine then you will probably run into some trouble, if you are going to turbo an autimatic you can save your tranny a lot of wear by improving the transmission fluid cooler, there are aftermarket coolers available, you coulc also look into a better tourque converter,
www.importperformancetrans.com has transmission build kits available for the 1mz-fe as well as cooling kits and tourque converters
edit: oh and as far as power there will be a difference in gear ratios of course