Hello peeps, sorry got alot of questions at the min as im new to mk4's

i have a mk4 van 17 dti 53 reg.

now i want to service the van next weekend, what items are recommended is any make ok ? ebay specials ?

also what grade engine oil is best for this engine, its the isuzu.

also thinking of getting the cambelt done, iv always preferd GM/Gates but cant seem to find any for the mk4 van, what would you suggest ?