I've heard mixed reviews of Honeypie Boutique - if you do a search on youandyourwedding on the forum you might find some experiences on there. They are made in China to the best of my knowledge, but I can't tell you that 101% as I don't know the owner personally. I am 99.9% sure she doesn't make them herself, and she definitely has no facility to try on. When I was still running Look Darling (as mentioned above, sold the business a few months back now) I sold a dress to someone who is friends with the owner of Honeypie and she said there are no trying-on facilities. And she didn't buy her dress from her friend... Make of that what you will!
There is a lady based in Glasgow who hand makes dresses, the company is called Flossy & Dossy if you google it. I've had one of her dresses as a bridesmaid and they are very nice. I think my dress was about £200 ish but I didn't pay. She will make bespoke for you within a few weeks.
Also there is Oh My Honey - not sure what her prices are like, but they are reasonable I think (under £500) and handmade in the UK also. She's based in Brighton.
I would recommend trying on if at all possible. You may be surprised what suits you and what doesn't.
In terms of gathered and non-gathered waists, a gathered waist will look like most of the Dolly Couture dresses - the skirt is gathered at the waist and attached to the bodice so that it flares out. A non-gathered will not have gathering at the waist. It's very hard to explain!!! A gathered waist is less flattering. A non-gathered will be more skimming and more flattering. If you compare the 'Linda' dress by Fancy New York with the 'Manhattan' dress by Dolly Couture, you will see the difference there. I hope that makes sense....
I have seen the Kitty & Dulcie styles at a photo shoot and they are nice quality (and longer in real life than they appear on the website - I think the models on there are super super tall). You can make returns there too if the dress doesn't suit. They're around £300 I think.
Also worth a look is Petticoats-a-Plenty. No personal experience of them but you may find reviews online.
Whirling Turban make wedding dresses and they will cost a bit more than you might want to pay, but they are beautiful quality for the money.
You can order Dolly Couture Pink Label styles direct from the USA and they are lovely quality and their customer service is 101% - you will probably be looking at £400 ish for one of those, depending on the exchange rate.