Copper Buck 'n' Cauld

I'm kinda surprised this isn't a feature, but Copper Buckets and Copper Cauldrons. Copper Buckets would be extremely cheap but could only hold water and creatures, Which wouldn't negate the functionality of Iron buckets which could hold lava, Powdered snow, etc. Copper Cauldrons would also emit a redstone signal depending on what was placed in the cauldron E.G: Powdered snow=1 Water=5 Lava=10.