Try the link below for one made by Hardin Marine. I think the sections can be clocked to give you the 180 degree-phased, 2 in/2 out configuration. The brackets are designed to be mounted to the head, so it may not be exactly what you are looking for. The one from Greedy is a nice piece, but the inlets/outlets are 90 degrees apart.
http://www.hardin-marine.com/p-14589...-polished.aspx
Pappy