I'm glad you didn't have any major damage.

Try to turn the crankshaft using a socket and ratchet/breaker bar on the balancer bolt. If the engine will turn fairly smooth you should be OK. I would definitely put some lightweight oil in it and...

Did you shut the ignition off or did the engine lock up?

Get a look at it in the morning. If it didn't throw a rod and window the block, you should be fine to have it rebuilt. If you have an engine oil cooler something may have failed i.e. an o ring or a...