Buying used engine. Condition unknown

[GTA_G20]

Looking for some advice. I currently have a boxster with what I assume to be a cracked cylinder head. Runs well but burning coolant.

Now I've sourced a parts car with flood damage 80,000 miles. The security unit under the drivers seat is corroded and the car won't start. If I jump the starter the engine will turn over but for electrical reasons won't start. Getting the car under $2000 if its a good idea or not is the question...

Any help appreciated thanks