Yeah, almost all the armoured vehicle crews available are for Europe or North Africa. The SEA/Pacific theatre is pretty much off the AFV-figures radar, with the exception of some Japanese (&, maybe, some resin sets).
This MasterBox set gives you one figure that would be suitable:
You may be able to modify this Alpine Miniatures 1/35 WWII US Tank Crew #2 resin figure:
This MiniArt set gives you one or two figures you may be able to convert:
Overall, though, the cost may out-weigh the desire.