There are no rebuild kits, so your best bet is another engine, but you have to be specific on the 3.2 for automatics and the 3.0 for standards.
The good news is, despite your situation, the engines are relatively bullet-proof and usually just need the front and top 60K treatment to make them like new again. While the engine is out is a great time to do these activities. In the car, the job is a bear.