If you don't mind crossing the border I can find you quite a few decent engines in Ontario Canada wreckers have you tried searching on line with car-parts.com or other sites
I have one that comes with the 4t65hd tranny.. tranny only has 65,000kms on it.. Engine has 195,000kms on it but is super super clean as I have popped the lower intake off to check it out... 750 plus whatever the shipping costs are and its yours... Located in alberta, canada..