This is an old thread and what I am about to write probably won't be useful outside North America, because of shipping costs, but I want to share recent experiences with a supplier of products such as microphones, audio amplifiers, audio mixers, audio recorders, foot controls, cables, adapters, etc. for musicians. They sell other products, such as factory-made guitars, but my experience with them has been limited to electronic items.
It is easy to find electronic equipment and related accessories commonly used in home entertainment systems, but ask at most shops about something more specialized and they probably won't even understand what you are asking about, let alone be able to offer advice or have what you need in stock. I recently purchased some items from Sweetwater in Fort Wayne, Indiana and was sufficiently impressed that I decided to comment about them.
They have a huge inventory that includes most anything a music entertainer might need. They sell at competitive prices. They packed my shipments well. They shipped promptly. They even called after each scheduled day of arrival to make sure I received what I ordered, that it arrived without damage, and that it was going to work for me. A big additional plus is that all their employees who deal with customers have extensive backgrounds in music, recording, and live sound and can tell you what has and has not worked well for them and others they associate with.
This is their website:
http://www.sweetwater.com/Their phone number is: (800) 222-4700
-Bob