Extra talos masks go a long way on any grotesque conversion. I have board game conversions, chaos spawn conversions, an ork warboss. They go a long way to tie things together.
I reeeaally like the the art on the grotesque lore page (p71) of the Drukhari book. Both the daikatana and the battle axe grotesques are awesome. I think aberrants could capture that same feel with talos masks, weapon swaps, and those little talos manipulator arms sprouting from their backs.