Gotta go with Dan, if you want more power in the Crossfire, I'd go with the SRT 6.

I suppose a good company could engineer a turbo conversion for the Crossfire, but I'd really, really want some references before I'd let them touch my car and void the warranty.

Also, I'm not so sure the stock transmission is really built to hold up under the stresses of 400 hp.

It's your car, your money, knock yourself out. Most folks wind up living to regret these kinds of conversions, but sometimes they work out ok.