If you own them, use them and then you will know after a few days or a week. If you have not bought them yet, why did you decide these two pans were better than any other pan? French cast steel pans are a nice choice. Copper with stainless lining is good but expensive.
Riveted handles are better than not.
Some kind of stay cool handle is nice but you can always put a handle protector on them if the handle is thin enough.
How much weight is too much is entirely subjective. What you will be using them for, how much flipping and tossing you will do all make a difference. Fill the pan with some ingredients and try tossing them around. Notice how tired your hand/wrist is after a few minutes.
I looked at an eight inch Mauviel copper pan in the store and it was so heavy I could barely lift it empty.
You can test this in the store even if you haven't bought one. Just go find some small weighty objects to put in the pan to simulate the food and see how much fun you'll have.