seltzer sparkling regulator manifold multiple

My homebrewing buddy and I are hosting an Oktoberfest party in a few weeks. We are gonna have hombrewed festbier, hefeweizen, Edworts apfelwein, and possibly a shwarzbeer all on tap (I'm stoked). I have an empty keg I wanted to make seltzer water in for all the non-beer White Claw drinkers at...