Garmin 296 with automotive pack does all the things that you require with a lovely display, excellent turn-by-turn directions and a really good rechargeable battery.
As far as eBay is concerned be VERY careful since GPS seems to be one of the 'bait' products for defrauding the unwary out of large chunks of cash.
Adams (either online or just wandering in at Biggin Hill) seemed to be the best in terms of price, helpfulness and out and out product knowledge...
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