What oil in Octavia tdi

Hi and sorry to have to ask as I am sure its been covered many times before but what oil do I use in my 2003 octavia tdi 110bhp elegance? Also what are the service intervals? I mainly do motorway miles if this makes any difference. Also the clutch pedal sometimes stays down and needs a little nudge with foot to lift it back up is this likely to be the clutch slave cylinder? if so how hard job are they or how much is it likely to cost to get done?

Any help would be great

Cheers guys and gals