jimny spark plug

hi guys
need new spark plugs for my jeep, been to a few motor factors they saying theres three different types ranging in price from £10 £20 + £60
its a fifty one plate with the y reg type engine with cam belt (not chain)
13.16v
does ne1 know which type i actually need?
i fitted last week rhino ray 2+1/2" lift kit, i highly recomend this product as its given me a great lift!
but still being very flexible over rocky cross axeling terrain.
i tested it up the strata florida this sunday. done really good.
little bit twitchy on the road.
bazz