HMR:
Not sure I'd agree with you about the 276 being 'more modern' than the SP 26xx - they are both pretty much the same generation. They are designed for different purposes - the SP 26xx is intended for pure automotive use (hence the lack of batteries), the 276 is primarily a marine GPSR but it has automotive capabilities.
The 276 is limited to 256 megs of memory, because it uses a small proprietary Garmin chip, the European version of the Quest ships with 243 megs of built in memory - that's pretty much the same amount, in my books.
The key issue that has to be considered in MadMikey's case is that he wants a GPSR that is suitable for hill walking. This pretty much rules out most of the 'heavy' ones - hence, my suggestion that he investigate the Quest. The 276 is a bit lighter than the SP III, but it's still too heavy to carry around in your pocket for any extended period of time.
PanEuropean