I think most of the online retailers who sell high-end stuff have people who can give you support when you need it. It's kind of strange though - Most of these online companies charge full list for their products. When I go to a brick and mortar that charges full list I get a demo and setup in my home. These online guys give you none of that and still charge full list for the most part. But to answer your question, I've had very good dealings with Audio Advisor and Music Direct. They had people available to answer my questions about the products and were very courteous and knowledgeable about what they sold.
On Line Audio Mail Order Retailers
What is the general opinion regarding various on line audio retailers, just to name a few, Crutchfield, Music Direct, B&H, Adorama, Amazon, Best Buy and many others. If you were going to order an item that was available at all of these big name retailers which one would be your top choice and why.