Please remember, never add anyone's Discord to do business if they're not a trusted user. If they don't do business on Elitepvpers (sales thread), they're most likely a scammer.
As for your original question, there are a lot of decent rotation bots out there. I personally use GGL - as does most of my guild. We're all Rank 1 + Realm First Raiders.
You can read vouches / feedback here -
Additionally, on that thread, there are instructions on joining the non-member Discord to arrange a free trial to try before you buy.
If you have any questions, let me know.