i am a size 20 on top 40gg and a size 16 waist.the woman serving in monsoon,nice shop for separates by the way, told me that i just wouldnt be able to get a high street dress to fit me so separates are a must for me. got one dress, very nice from a website that is sort of silky jersey material that looks lovely on, again woman in monsoon recommended online purchases or catalogues, great woman in monsoon eh. the website is:
http://www.grayandosbourn.co.uk/
a bit pricey but very nice. good luck, hope you find something!