honestly, stock. The boxed cooler intel provides is the best you can do for the LGA775 CPUs. The 3.6 will still run silly hot unless you somehow found one of those models with E0 stepping. Even then you will easily hit 70C under load without some sort of watercooling
sorry, dont know too much about watercoolers since I have yet to need one. try looking around the usual sites for reviews (anandtech, xbitlabs, firingsquad etc)
Definitely not all copper ... sure its about one and a half times better at taking heat off the CPU... but has about a third of the capacity for storing that heat (i.e., endurance)