To me, stacking copper is just more like a hobby. Not investment, because i don't think the price of copper will rise like gold and silver, even in the future.
I love panda coins, they're fabulous. But the massive counterfeiting made me worried. I only buy those with PCGS/NGC. At least they have more chance to be genuine.
1/10oz are easier to collect due to the price. So i think it's quite a good choice to collect as you would easily get a full set of all years and you wouldn't take too much risk.