MoD maps with the specific markings relevant to the armed forces (Training area limits, ERV's, CP's, etc) are not available to the general public but apart from the military specific information the maps are exactly the same. There would be no reason for a civilian to need them anyway.
I use Garmin Mapsource. Works with maps for Garmin GPS handhelds. Easily the best out there but unfortunately the one single word I would use to describe it is "expensive". The GB Discoverer maps will set you back 200 notes if you want the entirety of the UK!