Right the 'LNB' is already in place on the mini-dish and I don't really want to get into buying a new dish and yep Beryl, same here ... an LCD 32" Toshiba, seriously abused by the kids ... so the HD might be a red herring but then again the TV might be due an upgrade pretty soon and more viable with the dosh saved by booting Sky.
The difference between the 'Standard' and 'HD' boxes is a few quid, whilst the leap to recording version is a few hundred (ish - or just under I think, not done a lot of looking yet).
Another techy question please fellows if I may? ... do your 'HDR units' (see, I'm getting up to speed

) require any other connections apart from the satellite input, link to TV and power ... i.e. things like permanent telephone and perhaps a further satellite input cable ... I think the Sky Plus features require these?
I mention this as we have our dish wired to a home network hub, which means I can pipe it anywhere but it's only currently set up for basic Sky ... having to get an electrician back would defeat the object of the exercise.