Skimmia Japonica as a hedge

I'd be more inclined to use Prunus laurocerasus "Otto Luyken". This one grows to about 3 feet high by about the same wide and can be used for hedging - plant about 2 feet apart if you want a proper hedge, further apart if you want to just let them grow together.
Now the reasons: its a north east facing wall and that's a cold place to be in the winter - skimmia prefers a bit of shelter from frost (overhanging trees or a milder situation), doesn't really need pruning at all and, while it doesn't mind a bit of a trim, it's not too keen on being hacked back regularly. You would also need to select the right variety if you used it - there are male and female forms - you'd need one male for every five females if you want berries - which means that the male plant won't produce berries, the others will. There are also 6 or 7 varieties - you'd have to consider which variety you wanted, plus making sure you'd got at least one or two male plants.