Uninterruptible power supply

I am thinking of getting a UPS, but finding it quite difficult to get the full details of connections, etc.
Daniel Cohen wrote on :

Lately, for reasons unknown (and my electrician reckons unknowable without major testing) my earth leakage circuit breaker trips occasionally and takes out all my power. So I am thinking of getting a UPS, but finding it quite difficult to get the full details of connections, etc.

It isn't my computer itself that concerns me, as this is a laptop, but external hard drives that may be working when the power goes. I am quite happy to have my machine shut down, so that the hard drives will also spin down normally.

Things that concern me.

  1. APC is well thought of, but its own software seems poor. I gather that when I have a UPS connected there will be a setting in Energy Saver inviting me to shut down the machine automatically after a certain time on battery. I take it that this will automatically save open files. I am likely to be away from the computer at the time there is a failure. What happens if some program "cancels shutdown", as has happened to me once or twice (very rarely) when I wanted to shutdown or restart my machine?

  2. I gather the automatic shutdown is governed by a USB connection. Can this go through a hub? Otherwise one does not have enough USB ports. Presumably, such a hub if powered (which is what I have) would need to be connected to the UPS.

  3. Annoyingly, the APC model that does NOT have a USB connection will take British plugs, whereas the better model has the computer/kettle sockets. All my equipment has British plugs. I am sure there is a connector easily available, but I am wondering if I can get one connector and plug in a standard multi-socket into which the other equipment would fit.

It's really only the external hard drives that worry me (I am expecting to upgrade from my current PowerBook, but it is more likely to be to a MacBook(Pro) than an iMac). Everything else should not worry too much about power suddenly going off.