"Special" valve spring compressor, no I dont see any "special" requirements.
I recommend you do the "rope" method... Pull the spark plug, and fill the cylinder with a long piece of rope. Then rotate the motor by hand until you compress the rope. This will prevent you from droppping a valve, should you slip...
As for thermostat, I would not go lower than 180'F. Stock is 195 from what I have seen.