Yup, I also like to see natural materials in person before buying. Sometimes this just isn't possible, but there's two people I trust to pick out materials over the phone.
Steve from Flyfisher's Paradise is one person I trust completely to do this. I can describe what I'm tying, and Steve will search through his inventory to find what I'm looking for. He's always 100% honest with me, and he'll tell me if he has something that will do what I want. He NEVER tries to sell me something that isn't exactly what I need.
When I mentioned our upcoming PAFF Tying Jam, and that I was looking for donations for our raffle, I only got out like 30 seconds of an explanation before he wrote out a very generous gift certificate for us. No questions asked. Very cool!
Another person I trust to pick exactly what I need is Chris Helm.
http://www.whitetailflytieing.com/
While he has an online store, when you call you speak to Chris. When it comes to deer hair, he's the best there is. I called looking for a particular type of hair in an unusual color, and he rooted through his personal stash, found some patches of deer hair, and actually sat at his tying bench to see if it would work for my purposes. Now that's service!
I'd be remiss if I didn't mention our very own sandfly - owner of Big Meadows Fly Shop.
http://www.bigmeadowsflyshop.com/
You can call him, tell him what you're looking for, and he'll go to great lengths to get you what you need. If he doesn't have what you need, he'll get it, or make it. Sometimes his material source is still walking when you call. :-o