The SeismiQuery page at http://www.iris.edu/SeismiQuery/breq_fast.htm can do this. The user inputs query parameters into a form to delimit a BREQ_FAST request. The user may input query options including virtual network, a region defined by a clickable map, sensor type, channel name, and sample rate.
You want the BREQ_FAST request to get sent to <dataless AT iris.washington.edu> in order to get a dataless SEED and not a full data product.