The UK is covered by 204 Ordnance Survey Landranger 1:50,000 scale maps. Maps numbered 1 to 86 cover Scotland but for the highest mountains (Munros) only 23 maps are required. The name given roughly describes the area covered by the map.
You can click on the map name to purchase the map for £6.29 including postage which is one of the cheapest prices we have found.