Mike,
Feathered Friends probably has the largest selection, Marmot in Bellvue also has some things that they don't have, like Pika cam hooks and alien offsets...also, pro-mountain sports has a few odds and ends that no one else has....like the Kong Fi-Fi.
Talk with Jeff at FF, he's pretty knowledgable.
Get your aid on and we'll go speed up El Cap sometime...have fun, nice job in Red Rocks, sounds cool!
Matt