New sails. You could draw around your old sails on a piece of paper, and send the template off to a model sail makers. I am not sure who does this in the UK now. I am sure others will chime in.
Alternatively you could make your own. You can buy sail material from some suppliers. You will need sail fabric, eyelets and washers, and eyelet hammer tool, you can get from these guys
http://www.sailsetc2.com/store/index.php/products-by-category/sails/sail-making-materials.html. They also do custom sail making, you need to download the order form here
http://www.sailsetc2.com/store/index.php/products-by-class/other-classes/sails.html But I think others are cheaper than these guys as Sailsetc specialize in racing/competition gear.
A cheap alternative to sail material, if you live near a local chandlers, is to buy off cuts of spinnaker cloth. I got a meter for about 5 quid. You will still need eyelets.
If you are going to get them made, then have the pair made. They will match and you know that both will be sound.