What can be used to provide daily network usage reports on all layer 3 devices without compromising any data while gathering the information?

you can use Websense Content Gateway or SolarWinds Monitoring Suite, they can be configured to encrypt the data while it is collected.

Try Solarwinds products, it have a useful solutions for network and systems monitoring using various trafic types and protocols. and it have a MAP options that help you point device location in a geo-maps.