Some guys have bought the discount autoparts revuilt motors and run them. Thats the cheaps.. Finding a ready to go long block..$$$$$$$ get ready.. theyre expensive.
I would suggest getting yours rebuilt. But agian you didnt mention if you wanted a stock motor or one with a girdle, carrillo rods, steel crank, aluminum heads etc.. big difference in price.
If your crank/block is/are salvageable, then its probably cheaper to get yours done.