Wow, that sounds like a fun project! I hope you get some crazy ones out there... I'm always disappointed by the selection around Halloween. Well, it will probably be a ton of work but all things worthwhile usually are. The first thing I would try to find out about is how they are made... are there any high quality hand made ones? How were the first lashes made? Then maybe you could give it a go at making sample piece ones or even for selling on a site like etsy. While that's probably not ideal... the idea is to grow. I would also contact the companies that manufacture just your local drugstore variety ones, write to them about what you're looking for. Lastly, look into ebay sellers or wholesale sites... there are a lot of manufactures all over the world and sometimes if you find an ebay seller that specializes in an item they may be able to help you make your own. Like last yr I found a Chinese company that made Halloween costumes and even sold them wholesale... I contacted them and even though there were definitely language barriers he took my request and the picture of what I wanted and shipped it to me at a reasonable rate. He even offered me wholesale discounts.
Everyone has to start somewhere, if you have certain ideals you want to stick to when creating your company you may have to deviate and find ways for it to work for you. Definitely look into everything you can about running and creating a business in the UK. So my first piece of advice would really be to go get to the library with lots of enthusiasm =)