leak between 1 2 spark plugs? What is he talking about?
If you have spark leaks replace the plug wires. If he is talking about a leak between cylinders then that isn't diagnosed with a diagnostic machine that is diagnosed with a compression tester. Did he use a compression tester? If he heard a rattle in the plug hole then it sounds like he pulled the plugs to run a compression test, and if #1 & #2 cylinders failed the compression test then the engine is going to have to be torn down again. Do you know what test he ran?
Don't spend anymore on this engine. In my opinion you got some bad advice when your cylinder head died. If it died to the point that a piston had to be replaced and you had 90K+ miles on it the entire engine should have been pulled and replaced by a rebuilt engine. And if your going to do that then as another poster said your car was a prime candidate for a Zetec swap.
My advice is if you indeed are failing compression on 2 cylinders, then you need to step back and reevaluate this car. If this has an auto trans in it, then if it was my car I'd sell it. If it has the manual MTX hooked to an SPI then if it was mine I'd do a Zetec swap. But, you are a different person and you have to consider if this car meets your needs or not. These are small economy cars. Gas prices are not going down. If you don't need the room for kids or whatever in the future then if you were to drop $3-4K into a Zetec engine swap with a rebuilt Zetec you would very likely get a 50K mile warranty and be able to run the car for another decade. Even if you got a rebuilt SPI engine since the head is only a year old, you could buy a short block and someone competent to put it back together, and you would end up with a car that is worth $2.5K at least on the used market. And if you go out there and attempt to buy a used economy car you cannot touch anything that will run for more than 500 miles for very much under $2,000 because used economy cars today are white hot in the market.