for extra expense the satmap region premium are excellent value - albeit at a rather steeper price point. the south east (50k, 25k and 10k streetmap) at £380 is SO much cheaper than buying bits and pieces and is cheaper than my much smaller area "bits" at 25k i have. you can toggle between the different scales.
satmap national parks also come in combined 25k and 50k packages at good prices - again, toggle between scales.
you can navigate with a gps but a gps won't teach you how to navigate.
you will also need to learn and understand what a gps is telling you - is that dot on the map really where you are?
if you want to improve your navigation first - and i would suggest that this may be the best option to start with - then get a cheap gps that will tell you where you are and use this as a "where am i" backup to your map reading. having a gps should bolster your confidence in making decisions (always have the gps switched on and learn how to use trackback as a minimum) and it won't be long until you find you're not looking at the gps to confirm your position.
doing it this way will help you decide upon what kind of gps you want and what features you would find useful.
further gps type things like routes, tracks, waypoints, GoTo and "i know it's in one of these soddin menus" you can pick up along the way as these features are common to all gps units.
Edited: 11/06/2012 at 13:27