rollcasting roll casting fly

Hi, everyone. Would appreciate opinions as to the following query: which rod & line setup will rollcast a size 14 or 12 beadhead streamer the furthest, a 9', 4 wt medium action rod with 4 wt DT line or a 5 with 5 wt line or a 6 with 6 wt line or a 7 with 7 wt line? Can get those size wooly...