While the ting-a-lings people enjoyed growing up were made with Nestle's chips, we now have many more options when it comes to chocolate. We love Guittard chocolate from San Francisco, they have wafers which melt beautifully and are available in the baking section of many grocery stores.
We also LOVE the Belgium chocolate Callebaut for it's smooth, rich flavor. Callebaut can be found in large bars in some cooking stores, or in bulk at Whole Foods and other better grocery stores. Also, I am not sure, but I suspect, the large bars of Belgium chocolate at Trader Joe's are made of Callebaut -- either way, the bars from TJ's would be a wonderful choice as well.