Planted tank or artificial?
I have a 30 gal community tank, well cycled and well filtered. The thing is, my brother and I will start breeding guppies, im going to buy a 15.6 gal for the males and leave all the females (with more fish) in the main tank. We also have two 2gal for raising fry and possibly for raising baby brine shrimp.
How should we decorate the males tank? I was thinking shale structures with anubias on top of them with some taller plants in the middle. For guppies, should I get artificial or real plants?
Also is this a good setup idea for breeding?

Fish could care less, most hardcore breeders use bare-bottom tanks with nothing more than a sponge filter and an air pump. Breeding livebearers has more to do with the water conditions than the habitat, the setup should only matter when dealing with the more difficult species to breed like Chocolate Gourami’s. But I’m assuming you actually want a presentable and enjoyable breeding tank then most definitely go with real plants. Anubias sp, Microsorum sp, and Vesicularia sp all make candidates.