If this is the first time you've used a car forum, you might like this one!
For standard driving, then the EBC stuff will be fine. If you want a bit more stopping power then you could add Ferodo pads with the EBC discs. Our trader's links are on the front page if you want to have a browse. Any questions, just ask!
As for fitting in London, it depends how handy you are with a spanner! It's not hard at all to change discs and pads yourself. If you want someone to fit them for you, I would suggest a short drive out of London. One of the members from the Croydon / Kent / Essex ways will no doubt have some recommendations.