Even if it's "just a head gasket", you'll have a lot of money and time in the repair. The front of the engine will have to be disassembled to remove the timing chains. It's a complicated setup that will drive you crazy. At least it's in an Intrepid where the engine sits north/south, its worse on a Stratus because the engine sits sideways.
If the engine is too far gone, another alternative is to find a 3.2 V6 and do the swap.