try both, u can always take them off again when u fancy a change!
i am a fan of big bumpers but do like small bumpers on certain cars, for example another lad on here (veedubgti16v) i think has a Atlas grey valver with small bumpers, low with some nice rims, looks sweet!
So it doesnt matter what u choose, its still going to look the bizzle! In Oak Green aswell! nice!