If you buy a new genuine oil filter it will already have the seal built into it. You'll need a new oil filter, a new sump plug and copper washer, an oil filter removel tool (£3 odd from halfrauds), standard plugs will do you for your car, they'll tell you the right ones if you give them the year model and engine code. For oil i'd use 10w semi synthetic for the winter. Whilst you're at it you might aswell get a new pollen filter (essential for the winter to demist the front screen as far as i'm concerned) and a new air filter. If you want to give it a more hardcore service then consider a new distributer cap, rotor arm and ignition leads. Not a fat lot for them and they're a hell of a lot easier to do than changing oil.
www.eurocarparts.co.ukYour car is the 2.0 AGG engine
Part NO. Part Price
408770560 BOSCH SUPER PLUS WR7LTC SPARK PLUGS £2.53 each
501440105 GENUINE VW OIL FILTER £3.75
507440030 POLLEN FILTER £5.97
333440010 GENUINE SUMP PLUG £1.00
360440010 SUMP PLUG WASHER £0.29
404440100 DISTRIBUTER CAP £7.56
405440010 ROTOR ARM £3.70
409440790 FULL IGNITION LEAD SET £16.19
That will give it a hardcore service for not a lot of pennies and will keep it running spot on