Any suggestions for Runabout/Runamuck heads in an alternator/voyager size?

I have a commission for these twins, and struggling to find appropriate heads

 

i was told by a board memeber i think @ S70 to use a modded Alt Skids head F_R,
i think it might work with a couple of mods here and there  
hopefully that helps

 

Was hoping for a short cut, something with the visor/face plate to begin with. that's good though, I already have an extra skids here, I should open it up and take a look.

 

I actually put the skids head on there, but it's too small. I will most likely use the Sunstreaker or the larger type head and scratch build the details and features.
I might not go with the mouth plate, just because I don't think that look is very modern.

 

How about Grimlock?

 

that's a good one! the alternator right? I actually have one on it's way to me now. any idea offhand if his alt head is a smaller one (like skids) or larger one (like sunstreaker)?

I suppose I will share more about the customs so suggestions come easier possibly.

I'm taking 2 Crossover Venoms, and converting those into Runabout/Runamuck. making several mods to them, including replacing the hands with more robotish hands, adding the new heads, cleaning up some of the monster type detail on the car mode (which is awesome)