nothing wrong with cruising in an '03/04 cobra--great ride quality, no need for longtubes or a big nasty cam to make power. the car idles like it was stock, and no one would ever suspect you've got nearly 700 at the crank. 500-600 rwhp and these cars are completely reliable as long as you don't plan on beating the absolute piss out of it on a daily basis.
like i said, dial it back to a pulleyed car and you'll beat up on c5z's all day long, while maintaining complete reliability. whatever you do, don't sell it immediately with your emotions running hot right now--get a clear head, weigh all your options, and go from there