I've had a look at those suggested. They all do the job but most of the map technology is very basic and out of date. Of the freebies I found Notam Map the most intuitive - you can move the map about with the mouse and right clicking a symbol on the map brings up the Notam with the limits, times etc clearly displayed. All you need really.
Leg-it has a proper zoomable map with features and can be exported to Memory-Map. It is a macro-enabled Excel workbook (not the greatest idea) and costs £24.
All of these use an XML file from NATS. Does anyone know the url of this web service?