Also, will a standard cpu cooler mount correctly on these?
Probably not, even if you decided to void the warranty by opening it. Besides, there is basically one of the best cooling solutions on the market cooling the chips right now, why would you want to replace it?
I've seen my units go above 90C and continue to output 1.6TH/s. I hate for that to happen (it shortens their lifespan considerably) but they seem to at least operate at these temperatures.