I would think that either of these two would work:
http://www.greenleafaquariums.com/co...-splitter.html
or
http://www.greenleafaquariums.com/co...-manifold.html
Maybe give Orlando over at GLA a message or call to discuss the options. I'm no expert on this topic, so I don't want to lead your opionion one way or the other. I have spoken with Orlando over the phone, and he really is a great guy to deal with. I particularly like it when I don't get the 'salesman pitch' from somebody trying to get me to purchase a more expensive option. Orlando is a straight shooter, and will help analyze what will suit you best, which may differ from what may suit his wallet best. A top notch guy if you ask me.