I've ordered thread from Red Rock Threads and Quilting Warehouse and had good threads and service.

http://www.quilting-warehouse.com/thread-coats---clark-starmercerized.html#.U0b8UqLfLQc

The Star is unglazed, but I threw it in because I know some people swear by it and the price may be part of the reason. It's a 30 weight and I've wanted to try it myself. Red Rock carries Star, too, but you get a little better price at Quilting Warehouse.

Red Rock carries YLI , too.

Here is a link that might be useful: Red Rock Threads

Do any of you know of a reason not to use machine quilting thread to hand quilt? I feel limited with the hand quilting choices and feel there is a greater choice with the machine thread.