Is it anything goes for registry weddings in the UK? I thought it was a bit more suiting/tailored in nicer fabrics? I had thought of Roland Mouret also, Roksanda is also worth a punt and Victoria Beckham does do nice white pieces but assumed full on gowns would be too much?
Personally I'd probably get completely stuck on shoes. I really don't like those traditional white silk pumps but there's not much choice out there in white, although it is a bit of a fashion colour in shoes at the moment.
denimes, I did get in a 15% off and free shipping code from Net A Porter this morning, you're welcome to have it if it's of any use to you. Although I'm not sure if it's regional or tied to my account, their codes are a bit peculiar.