Thanks for all the help re the cider, lads. I'm looking forward to when I get the chance to start making it. Spud, would you recommend putting the tea in when your mixing in all the other ingredients, before adding the yeast?
Taffy, there's a health/natural produce shop up the stairs in Paul Street Shopping Centre in town. They have a small section for homebrew stuff. The supply is fairly limited, though, so you mightn't get exactly what you're looking for. It's also more expensive, as well as limited, than online shops, so you'd probably only be best going there if your buying fairly small quantaties of stuff (eg, a sachet of yeast).