Actually, Welsh men these days have a kilted outfit that is pretty run of the mill as these things go, but popular and available on rental from most men's outfitters. Traditionally there is an outfit comprising knee britches (clos penglin), short jacket (often blue) and waistcoat. White stockings and black shoes with silver buckle. Flat quaker-style hat.

Re: women's dress, there was an excellent exhibition in the National Library recently which brought home the major differences in regional Welsh dress. The tall hat wasn't ubiquitous, and even tall hats varied in shape where they did take hold. Not many the shape of the kiddies' version you see on St David's Day. Many working women wore cockle-shell bonnets or version of the 'Jim Crow' hat famous throughout Britain. I guess red or navy hooded capes were pretty popular all over Wales.

Re: English 'national' dress, what nation? Far more interesting to have Cornish dress, Norfolk dress, Cumbrian dress, etc.

sian