Can't help you much with the timing belt, I don't know one way or the other.
As for the oil filter, it's at the front of the engine all the way at the bottom. I haven't actually tried to get my hands or an oil filter wrench on it yet, but as near as I can tell, the only way to change it is to remove the front skid plate. If anyone knows of another way I'd love to hear it.
Steve Gold 03 Limited V8