Sony RDR-HXD770. £200 from Argos, though may be cheaper elsewhere (and apparently was £150 around last Chrimbo). It is "only" 120gb, but that still accounts for something like 30 E180 tapes in space at good-high quality. Also someone on AVForums has step by step notes on placing any big old SATA drive you like in them, so that will be fun when the warranty runs out. It does cost more, it's true, but I certainly would say to ignore disc size in any comparisons, I think features and quality are more important.
My parents also have a Bush DVD recorder they never use- I mention this because the Warfedale HDD/DVD recorder currently on sale is the same thing, but with the HDD added and a different facia. (It was clear from the Bush manual/remote that it could have a HDD in some models). That didn't have a way to control an external receiver, and an annoying habit of changing the input to analogue TV every time you came out of watching something. What you won't get with the Sony is any way to record HD I think. It basically records from its SCART.