Android Emulator - 500 android Accounts Automation

Looking to create a system that will allow me to have access to 500 android accounts to do app testing. I would also like to be able to control these accounts and have repeated actions taken on them as well. For example, I would like the ability to have them all download and install the same app. This is not a must but would be a nice feature if I could easily control and automate the actions. I know that getting phone numbers to test on these accounts is also possible with some APIs. Looking to speak with someone who can help us create and build this system. Looking for it to be very cost effective, its okay if there is some monthly charges for keeping it running but would like to keep that a minimum. I am open to any ideas to make this work. They could be hosted on a VM, a andriod phone itself, etc etc.