Wouldn't it be cheaper to knock up your own in A6 format (4 per A4 page) then just get them photocopied? That would cost you about £12 by my reckoning.
I'd go with alchresearch! You might also be best of posting (or getting a mod to move this thread) into pets section. Lots of pet lovers on there who'll help you out/give you advice!
I have a missing cat and require some leaflets that i can go door to door with anybody know of a cheap company that could help.
I noticed some posters on lampposts outside Windmill Hill school at Burncross
regarding a found cat.
It would be usefull if you put your location on your post to avoid getting reports of found cats all over Sheffield.