I finished the second Combi-weapon Bearer so it is officially now a thing. For my second attempt, I chose a Combi-gravity from the Sternguard plastic set. I wish I knew the names for the side-by-side vs the over-under Combi-weapons but I do not. I would love to be consistent with my conversions, but there are a lot more over-under weapons than side-by-side.
As for painting, I used Agrax Earthshade to shade the robes rather than Sreaphim Sepia which accounts for the differences in color tone. I chose to paint his cute little feet blue to match the Gravity effects. I know that I paint my Plasma weapons blue too, but I don't care. The Gravity weapons are visually distinct from Plasma weapons enough.
For the value of this mini, I would put it on par with the other Combi-bearer ($30). The conversion work was a lot less than erasing that evil metal helmet with a Dremel. It mainly consisted of clipping off the sword and re-sculpting the mini a little.