ouch!

A few weeks ago i went on a road trip...well on the way back, i was getting about 17 mpg. Car is a 04 Mustang GT. 30,000 miles with a P-1SC on it. Since the gas mileage was terrible, i did some checking. Found 2 spark plugs missing their grounds, and 2 with grounds smashed up against the casing. After i replaced the plugs, the car started knocking really really bad. I decided to tear the engine apart...what i found was not pretty. See pics below.

So now that i have to replace atleast 2 pistons, and also atleast the drivers side head....what should i do? I'm on a tight budget, but want to do an educated buy. Any clue how much it would cost to replace the parts with stock parts? I tried looking on autozone for a rebuild kit, but cant find much. I might go the boneyard route, not sure yet. Also while the engine is pulled, might as well put some headers on it...anyone know any used headers for sale?


***edit*** disregard the red circle on the spark plug pic...it was for other reasons.

Thanks,
Bob

yeah it does suck...especially since these cars are a true pain to work on. Ford puts some of the brackets in some really funky places!

Oh forgot to mention...when i pulled the intake plenum i found large pieces of metal. The pieces looked like a piston ring, but still not sure yet. I'm going to pull the engine, then pull the passenger head to further access the damage. Unfortunatly i dont have a pic of the pieces right now, the pieces are at work. The pieces do baffle me though, some of the pieces are atleast 1 inch long. How does a piece that big end up in the plenum? How am i not burning oil if it is a ring? Why are the pieces fairly straight? Really stumped on that one. I'll know better once i get the other head off.

Heres a pic of the drivers side head thats messed up.

blower is in great condition...spins freely, and no marks on the outlet portion. Trust me, I'm treating every aspect of this right now as a crime scene. Also looked at the throttle body, no markings there either. Only 2 conclusions i can have left...1. ring on passenger side chewed up and worked over to other side (i know doesnt seem feasible) 2. someone dropped something in the plenum and caused problems.