We need more info man what kind of area you working what size gold how far do you have to carry etc.I have jets and suction nozzles for all my dredges there is a place for everything.I also own all 3 brands you mention.Again they all have there place I am partial to Proline they are well built.Im sure others will chime in if you post some more info.
Hose plugs are dependent on the user, not the nozzle. For a 2" backpack dredge I would say to go with a suction nozzle. You are probably working mostly shallow material and this will prevent the problems from accidentally sucking air.