I'd be very happy to use the iPhone - which apps use the gpx files? The other problem is battery power, I'd really be aiming to have it switched on all the time - I hear gps devices have a much longer battery life?
As for the map reading - believe me, I've tried and failed, the invention of the SatNav changed my life, I'm hoping for a similar solution for the bike.
I'd happily recommend ViewRanger. iPhone, Android and Browser software, almost free to buy. Software is excellent for creating and following routes
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