Looking for Yarn...on a mission from God...no really!

I live in southwestern Ohio...and am on a quest to find some yarn to make a going away gift for our church's pastor. She's been with us for 3 years...and has been called up to go to another church quite unexpectedly. I would like to knit her a pictoral purse or a Bible bag. The 'picture' part of it would be of our church. I came up with a way to create a knit, embroidery, quilt pattern in photoshop by taking my own photo and turning it into pixels. I posted the tutorial on Craftster with my Marilyn Monroe cross stitch and quilt projects. I'll see if I can post the link here or not. Anyhow, I'm looking for yarn which would have great values from black to white. I'm having a hard time finding silvery greys.
*UPDATE*
I found a couple of fabulous local yarn stores...but not in time to make the project I had in mind for Pastor Pam.
This is what I came up with instead of the knit bag...