I assume the sound of M3W as laud as a Harley Davidson motorcycles and these bikes have a sound system pre-installed in them by factory. So why not a M3W?
While music and 1000 miles a day
may be possible in the Morgan, if these are your priorities then you really need to drive one and decide yourself. It would not be my vehicle of choice for music or long distances.
Having said that, the factory intercom works fine and has an input for music but does require a full face helmet which negates it's usefulness.
Good luck with your trip across Europe