I would doubt there are any / many differences in recommendations between the US and UK, although the voltage is different. You would want a dedicated line for your amp(s) and one for the remaining audio components. Use oversized wire… 10 gauge and audiophile outlets. Special audiophile grade wire for running dedicated lines is available… I am sure this would be a little bit better… but this could start getting costly. Here the value now and in the future of your system should be taken into account.
I don’t think it is as important, but since you are doing all. The same for your AV system.