As you know acolytes with meltas add the tank-busting the GK inherently lack, so they're a good choice. What model do you plan on using for this unit? Power-amour is the way to go I think so maybe a SM scout of some kind with melta.
Next note on the inquisitor faction is perhaps drop a unit of acolytes and pick up 2 Jokaero Weaponsmiths, SPACE MONKEYS with lascannons! Not only are they a cool model but i think they get the job done you're looking for while buffing our the unit some more. Overall I've thought about doing something similar with the inquisitor detachment to save points on bringing Crowe or Draigo
Next note on the inquisitor faction is perhaps drop a unit of acolytes and pick up 2 Jokaero Weaponsmiths, SPACE MONKEYS with lascannons! Not only are they a cool model but i think they get the job done you're looking for while buffing our the unit some more. Overall I've thought about doing something similar with the inquisitor detachment to save points on bringing Crowe or Draigo
