I've seen similar in Monsoon and Accessorise - you may have to get two separate ones which either clip on or sew on though as I can't recollect seeing any double ones. If you want them made in silk flowers, it may be difficult finding the flowers in satin. Hope that helps.
www.rainbowweddingflowers.co.uk - Designer silk wedding flowers - bespoke service throughout the UK. email rainbowflowers@paulandbrenda.demon.co.uk 2012/2013 Brochure on request