The white cubes are nice looking if your house is (decorated in) somewhat modernist style. They are called "Plant Pot Decoration " so clearly they are meant to have an actual pot (with drainage holes) inside. It doesn't seem like it would be that hard to find ordinary plastic nursery pots in smaller sizes to go inside of them. Just remember you also need to have pebbles or pot feet or something under the nursery pots so that they do not sit in the water that drains out. So it just means you have to go several sizes down. Plastic nursery pots come in all sizes from gallons to tiny. Check out
https://www.greenhousemegastore.com/category/containers
for a cheap on-line source of nursery pots.
Personally I don't much like the look of the fake rock one. Fake things usually end up looking fake. It seems like it would need a whole different décor style, much more rustic/country to incorporate the rock into. The décor style that would harmonize with the simple white cubes would be very different from the one that would harmonize with indoor rocks. And whatever rock illusion the pot managed to create would be totally destroyed by having a saucer under it.
I've never tried growing in bags, so can't say much about them, but off-hand it seems like it might be harder to keep the bag up out of the drained water.