WordPress staging site a a great way to test and work on new functionaltiy.
We have tremendous experience with staging sites. We've launched qSandbox.com & WPSandbox.net platforms just for that.
We can set up a private WordPress staging site that's password protected and optimized.
The server can be as close as possible to you or where your developers are.
The server can can be a dedicated server from a provider that you choose or one that we work with.
The disk storage can range from 5-10 GB to 5-10TB!