There’s no way they would use British umpires for this series - the game would be far too fast for them. MLB will send a regular crew.
EDIT - Just saw that the Saturday game will have Ed Hickox behind the plate, with Carlos Torres, Dana DeMuth and everyone’s favorite, Angel Hernandez, first to third with the normal totation for Sunday.
Since you bet on just about anything over there, I wonder if there’s an over/under on how many calls Hernandez will screw up? Tougher to place s number when he’ll be at 3rd and then 2nd.