At the moment, Five has gone to the other freesat, but Fiver and Five US are still stuck with the Sky freesat only.
Looking for other worthwhile channels:
Sky have a couple of film channels that the other freesat do not
The other freesat has Zone Horror, Sky appear not to.
Before deciding on BBC/ITV Freesat or Sky Freesat, or even Sky multiroom - extra subs, but you get your full channel packs on all multiroom boxes, have a glance at the channel lists for anything you really want.
If you are going to do it the no extra subs way, then:
1. you need a multi-output LNB - dual will drive one additional box, but for anything more, or an additional recording box with dual tuners, you would need a quad.
http://www.argos.co.uk/static/Produc...%3EFREESAT.htm - Argos Quad LNB for Sky dishes, looks like the cable kit with it is only enough for a dual hookup.
http://cgi.ebay.co.uk/BRAND-NEW-QUAD...1%7C240%3A1309 - Universal, claimed to fit sky dish and only £9.99
2. Buy a box, for BBC/ITV Freesat you would probably be buying at Argos or something.
£299 for a recorder (HD), £120-150 (HD), about £50 for standard def
For Sky Freesat, you would probably buy the box from Ebay, and if it has a matching card, that MAY work as a Sky freesat card, otherwise it's £20 for one from Sky.
Look up the model number of any box you are considering, several older models are notorious for power supply faults, failure to restart etc.