Hi Patty!
Sorry, I can't help you on the magic shows, but Darrell always makes a stop at the magic shop in the Riviera when ever we are in Vegas. It's right across the hallway from Katy's coffee shop in the Riviera.
They have all the standard fare (rubber dog poo, magic rings, card tricks, etc.) plus alot of fancy slight of hand props and a good selection of books. If you are staying at the Riviera, there is a discount coupon in the Fun Book that you receive upon check-in.