OK, I can finally update anyone who missed the last couple days on what has happened. I had decided to wait for the solving of the clues till I would post again.

First we recieved an update from paradisesage that someone had gone to the airport for us and posted a video and an audio clip to youtube, which were eventually uploaded to the site. The videos are here and on booksofhistory.com:

http://youtube.com/watch?v=W93pdrOQ6YA
http://youtube.com/watch?v=ETsKDfOP3XE

In the first video we find out that our person went to the airport and recieved a folder marked MB, an index card with the number 615-750-9255 which he apparently called and it was answered by stroud. He also recieved a cd with the second file on it and these letters around the edge starting from the 12 o-clock position "qtd5r0b000"
Here is the transcription of the audio file for those that cannot see it:

"Members of the Circle I thought I would stop by and say hello personally. You know me already of course, LaFontaine, Stroud, MacElroy; I go by many names, one can never be too careful these days, what with identity bandits and all. I suppose I should apologize first, you were probably expecting a message from someone else, a key to discover what’s behind door #3 maybe, or an envelope that had a, uh, a book. You figured out by now that this Marsuvees fellow was not at the Nashville Airport, you can consider it our little secret. It was necessary of course, I need to show you that I’m controlling things here, not Kara, especially not Kara, and not that megalomaniac in black, but hey, you know, anyone willing to drop a cool fortune to buy a blank book has to have some bats in the belfry, right? You’re a resourceful bunch, I’ll give you that much. Believe me when I say—when I say that you’re in over your heads this time. But you have a certain spunk about you, I like that! I like that! You know, I’m a capitalist at heart and I believe in free markets, competition, all that, so… I’ll encourage you to keep trying. Giving Black a run for his money can only put more into my pocket. If you think I work for him, no, you should probably think again; I’m really just a free agent. Consider me the Randy Moss of book hunting. This is the most fun I’ve had in a long time, folks. So… let’s take it up a notch, shall we, and write a story that’s REALLY worth telling? So listen closely here. Under the earth I go, on the oak leaf I stand, I ride on the filly that was never foaled, and I carry the dead in my hand. I have a book in mind that goes by another name. If you can tell me what it is, I might give you a sporting chance to get this book, the one that Black wants. If you can best him, it’s yours. But you don’t have a whole lot of time. I’ll wait for your response in my little space of the internet; I think you know what I’m talking about and where to find me. Catch me if you can!"

Later, after waiting for an answer from stroud on his myspace page found here:
http://profile.myspace.com/index.cfm?fuseaction=user.viewprofile&friendID=268152455
he posted another blog with another clue:

Under the earth I go...

Round and round we go, but which book I mean nobody seems to know...yet.
A hint for you: a rose by any other name would smell as sweet. And, no, it’s not Shakespeare I’m looking for. Sometimes authors write a book with one title in mind and end up with another. Even Teddy knows that.

and after it was answered he blogged:

None of us is as smart as all of us.

So my friends, it looks as though you’ve been working together and have solved my little puzzle. You’ve figured me out. Caught...for now. It’s about time, really.
"Under the earth I go..." is an ancient bard’s prelude known as the "Storyteller’s Introduction". And "Storytellers", if you’ll dig a bit, turns out to be the original title of the book now known as "Showdown". A rose by another name.
Bravo, friends. Bravo. I guess you are serious about playing for keeps. I’ll be in contact with you soon. Looks like we have a game...or shall I say a showdown.
Stroud

The answer was guessed after many many attempts when sombody happened to see that in the signature edition of showdown it mentions the other name. Obviously, we are now waiting for him to contact us.