They used to have a good name and I'm not dissing them Zermatt as I've never used them. I'm just going by what a couple of local tyre fitters have said to me recently hence my reluctance.
Coatech are usually very good. Only ever seen one not so great job done by them. You could try Diamond Wheels in Dundee. I've not used them but a couple of friends of mine have and were impressed.