I have just picked up a Data East Royal Rumble and I am thinking about putting LEDs in it. After doing some reading I have learnt about LED ghosting/flickering that seems to be worse on Data East machines. Can someone please give opinion on this and if I need to source LEDs that help reduce the ghosting.

While I can't really comment specifically on Royal Rumble, I do have LED's in my DE Starwars and never had a problem