Not sure how much it will be out there, but I just entirely replaced my engine. Used the old heads (had them services though), dropped in an STI block because I got it at such a good deal. I also replaced all the peripherals, IE: oil pump, water pump, timing belt, pulleys, **** load of o rings, plus all the fluids. Between labor and everything, I dropped about $6000. I actually spent more than that, because I replaced a CV axle, put in a stage 2 Competition Clutch, and filled my tranny and rear diff with Amsoil gear oil. The $6000 is just for the engine related stuff.
That may give you am idea of how much it's going to cost you to replace / rebuild.