Hi Fiona,
are you setting up sites with static pages for couples? If you do it all manually and don't have a complicate database driven system that would dynamically use those templates, than you can just Google for "templates".
If you don't mind spending some money, you can by none exclusive professionally made templates at templatemonster.com - here is their Wedding section http://www.templatemonster.com/category.php?type=0&tid=+-+Any+-&search_words=+-+Any+-&from_=&to=&cat=75&style=0&author=0&x=28&y=11
Here are some free templates: http://www.templateyes.com/html-templates.htm
Or as I said Google "templates" or "free html templates".
You don't have to buy or download a whole bunch of them - pick a few and then change elements - colors, images etc and you will have a good variety.
Hope this helps :)
