Depends - if Clubman, I'd definitely go for pepper white/black. If the hatch chili red/white is a pretty classic combo although the hatch also looks very good in pepper white/black. Not to throw a spanner in the works but lately, I've become very partial to chili red /black on hatch or clubman!!!
To be honest, the Mini is one of very few cars in the world that seems to be able to pull off any colour - I've even liked the mellow yellow ones that I have seen and there aren't too many cars I can say that about (I hate yellow Ferarris and Porsches!!)
I was going to have them on my Dark Silver MCS but quoted about £700 fitted by my local dealer - given that the full kit was "only" £1200, I decided against for the time being. They do look really nice though as I like the Aero front and side skirts but prefer the standard Cooper S rear.