Got mine here:
https://www.arnotteurope.com/bmw-x5(...-products.aspx

However, they are made in the US...can't help with shipping costs I'm afraid.

They are well made units. You will need a monster torque wrench, 22mm sockets and a very thin spanner/wrench to remove the link. Be sure to mark the position of the nuts on the strut towers before removal. Try not to break the little pin that secures the locating tab, when you separate the old unit from the strut. Don't lose any of the jointing parts where the air line attaches to the strut - you may need them.

You might want to check for play in the ball joints on the sensor levers, as they corrode quite badly which leads to play, and system error messages. The new air springs seal to the strut with double O rings - you will need some silicone lubricant on these - and they can be difficult to seat fully. Just be persistent.

Jack the car in the centre at the front, and lower once both are done. If you jack each side individually, the system gets confused. The fronts need to be lowered to the ground together. You can use INPA to set the ride heights if necessary