Hi John, your account manager or Customer Care can help you set this up.
You do have to pick which metrics and dimensions you want included, though there isn't a limit as to how many you can include, and you can request multiple independent streams. This is done to preserve bandwidth and processing. For example, if you received a stream of everything available for a visualization that displayed 30 metrics/dimensions, you'd still be processing then discarding 90% of the transferred data (300+ metrics/dimensions).