It's impossible to list here all component manufacturers as there are far too many of them. In any case Google or your favourite search engine are there to help. But for convenience I've listed below some of the main names that you might want to try. Where the link is to a manufacturer their site will usually have a page listing their international resellers or distributors. Some even have an on-line store where you can purchase direct.

Be aware that imports from outside the EU will be subject to import duty on the total invoice value including shipping charges. VAT will then be added to that and the shipper will likely charge you for handling the paperwork.

WheelieBytes is my general site for cycling around the southwest London "burbs".