Would all Garmin devices allow me to use maps from here?

Looking to buy a unit, something similar to this one:

[Please Register or Login to download file]

but also like to have the option to add maps to t from here, e.g. USA, Canada and parts of Europe when going on holiday.

Would it work? Would the life time maps update continue to work once I add the other maps?

TIA

Yes if you will patch the firmware and learn how to install new maps !