Yeah, Barclays used to have loads of branches in SA, but the anti-apartheid movement (UK) campaign led to them losing tons of business, so they pulled out. Then when apartheid was abolished, they went bcak in, I think it was via buying out another bank there. vito will know, or be able to find out.
Anyway, Barclays have hundreds of branches throughout the UK, I think, but certainly in England and Wales.
HSBC are worldwide, with branches in many countries and, again, hundreds here. Both have good internet banking facilities so either would be a good choice for someone who couldn't visit the branch regularly

in my opinion.