There are links to various brush packs in the manual, here:
I don’t personally know of any that are a good match for those artstation brushes but someone will probably be able to give advice soon.
On this forum there are many people who’ve made large or small bundles of brushes available.
You have @Rakurri’s and you might want to try the set from @fizzyflower here:
There are others if you look for them or someone may suggest a link to a topic.