What type of oil in dampers?

[H8NSKPAUL]

I used extra heavy motorbike fork oil in the end at £7.20 +vat for 1 litre(which is all you need). Also, yes you need to fill both the inner and outer tubes equally to about an inch from the top or you can't get the tops to screw back in. They are rock hard now and just the tyre seems to give.
The car should step out big time now!!!..... AWESOME!!!!
Many thanks for your advice guys.
Cheers, Hans.