You know you aren't really supposed to be here. Thelion prefers to do his business out front, where he has all the displays. Once you decide what you want, he'll send me to come back here and get it.
Oh well, since you're here anyway now, I suppose Thelion won't mind just this once.
Back here, not everything is labelled, but if you know what you're looking for, it should be on one of these shelves.
If you need any help, you really should go and talk to Thelion. If you're lost, you can get back to the shop through that curtain, or you can take the path just outside this door. It will lead you right back to the front gate.