when having a quilt long-arm quilted it is not first sandwiched. the backing is loaded on a roller and rolled up, then the top is loaded on another roller and rolled up the batting is placed in between and (floats)
there is a list of long-armers here on the board, type in long-arm quilters in the search and you will find lots of them, there is also a Machine quilters Association, you can access and the professional quilters association.
good luck