Spend $ on professional diagnosis and current state of your car. Hope the auction price was right.
IF you need to replace head gaskets, have a plan to work on other items at the same time. The plan is best executed based on solid diagnosis about what is good and what may be bad.
Here's some simple and cheap things to do...Oil in coolant? White smoke on acceleration? A few cheap items to rule out include: Replace the thermostat. Replace spark plugs. Swap coil packs.