I suppose it comes down to a choice between gold and green! I would look at the planting in front of the position of your new hedge and imagine the two colours. Which would show off your plants better?

Green is an excellent foil...I know which I would go for.

I don't think Cupressus macrocarpa 'Goldrest Wilma' will be as hardy as Thuja. You can still get golden varieties if colour is a problem. Knocks spots off Leylandii every time.

Agree with previous answer - Wilma has a tendency to brown in wind, particularly cold winds, or in winter generally.