FD Gerbox Oil Recommendations

[Spike]

Hi Fellow Tossers, Plesae would someone end my confusion. I own a 2000 R850 GS and want advise on what Oil to fill the FD and Gerabox with. Im confused about whats best for the bike nad have alson tried to track down availability. I have reda links that suggest SAF-XO and Mobilube SHC 75W90 have you triede getting some?

Spike

 

[Gas'd Off]

Either: Castrol EPX 80W-90 (see bottom of page) Mineral oil from Halfords (check the label to make sure it says "GL5" that is important).
Or: My personal choice - Silkolene 75w90 "Silktran Syn5" - High spec synthetic. Do a google to see what it is. edit: See here for description.
Final drive takes 250ml

 

[Spike]

Either: Castrol EPX 80W-90 (see bottom of page) Mineral oil from Halfords (check the label to make sure it says "GL5" that is important).
Or: My personal choice - Silkolene 75w90 "Silktran Syn5" - High spec synthetic. Do a google to see what it is. edit: See here for description.
Final drive takes 250ml

Great thanks for the advise