Rep Power: 280

I'm still trying to figure out my overheating and heat problem. So far I've replaced the radiator cap, thermostat, coolant, and oil. Checked the fans, did a compression test, and I still have no indications of what the problem is. Short of me calling all the shops around here, what shops for sure will do a leak down test? and how much should I pay?

Also what else can I do to track down the problem without spending a fortune on parts and labor?