Sounds like a nice build, thanks for posting. I think you should get close to your power goals if not attain them.

There will be some big power RS6's coming out of WA state very soon, 700-800awhp range. The problem is the engine has to be dropped for just about everything, and it takes two large, expensive turbos to make big power on these cars, and when I say big power, I mean double the stock rating. Not only that, but all the fab work required for headers, downpipes, fuel system, and a new intake as our tiny airbox is restrictive above chipped power. There's not tons of room to stuff those big turbos, and not really worth while until you do a manual swap, yet another large expense. You can get a couple hundred extra ponies and a few hundred extra ft lbs with RS6-K04 based turbos, but to notch it up from there requires much much more time and money. This is why we haven't seen much of this, it's one of the least cost effective Audis to make really big power with. It does start with 450 from the factory, which isn't too shabby, and they put together a tight package that is time and $ to mod. 11 years later, we're finally seeing these cars get pushed as there's a nice handful of manual cars to play with now.