niggle wrote: All suggestions welcome!
Buy a GPS which has a suitable bike mount. It will be rainproof and have a much better battery life.
It looks like there is going to be a new SatMap available in the not too distant future. This has been rumoured but the fact they have recently been selling off existing stock at a significant reduction and now have no stock available suggests it will happen soon. The new model is supposed to have a better screen (not that the current one is bad) but smart 'phones have shown how good a little screen can be and GPS screens need to catch up. Downside is I guess the new model may well be pricey.