A multiswitch is probably the best answer. You need a different type of LNB though. The regular Sky+HD quad LNB won't work properly with a multiswitch. You should look for a Quatro LNB.
The
aerial (correct spelling
) can be connected directly to the UHF input of a 5 input multiswitch if you wish. Four of the inputs are for the satellite dish feeds, the fifth is generally wideband RF which covers the analogue and digital radio bands (FM and DAB) and the frequency range used by digital TV. The multiswitch combines all of that and sends it out on each output leg. At the TV points you'll need something to split the signals back in to their constituent parts; and that something is usually a quadplex wall plate which provides two satellite feeds, one TV feed, and one FM/DAB feed.
Whether your CCTV can go via the multiswitch depends on two things. First, does the CCTV recorder have an RF output? Most of the budget ones don't. That's not the end of the world though because it's still possible to buy video to analogue RF modulators. This then leads on the second question: Do the TVs all have an analogue tuner? Since the demise of analogue TV broadcasts which have been replaced with digital there's not a broad requirement for analogue tuners in TVs for broadcast signal reception. Analogue tuners are still useful though for picking up distributed Sky from RF2 and for viewing CCTV if it is ported in to the distribution system as analogue RF. However, fewer TVs are coming with them fitted. It is possible to buy a video to "digital RF" modulators, but they're a lot more money than the analogue versions: think £300+ as a rough ball park figure. If the TVs have no analogue tuners then it's probably going to be cheaper to run a separate distribution system either on composite video or HDMI (either straight or via HDMI to Cat5/6 baluns) and then switch the TV to an AV input when you want to view CCTV.
Coax cable: Go with Webro WF100. It's a slightly different construction internally that makes it a little more robust for routing. Don't bend cables sharply though. Think about going around the base of a decent sized coffee mug as the tightest bend radius.
Finally, whether you need boosters on the aerial signal isn't something that can be answered without a site survey. So while you can spec and by some elements of your distribution system yourself, there are some areas where it pays dividends to bring in a professional aerial installer with local knowledge and a meter. That way your switch will get a clean and high
Quality signal (more important than strength) of a appropriate power for distribution.