mpsautosalvage.com has a 2003 cobra engine, transmission, and just about everything else under the hood up for sale as a package. You're probably looking around 15,000 for it... probably a lot more.
I'm rebuilding the new engine for my car, but it's a more torque-ier pushrod engine :-D So the swaps aren't very similar.
I'm going to retract my statement about the 15,000. I'm going to say more like 20-25,000. MPS is notorious for having overpriced salvage parts; however, those engines are prestine pieces it would appear.