p38 adding 20'' stormer alloys

morning all ive just brought a p38 dse and im looking to update the alloys to 20'' stormer which i have just brought from a guy who had them on his 2004 vouge

do i need spigot rings and nuts as ive already got non standard p38 alloys ?

http://www.landyzone.co.uk/photopost/uploads/71268/photo_2_.JPG

ive added a pic for u to see my current wheels

thanks in advance