You could just do it with a graphics package, like Paint Shop Pro if you pixellated the image and reduced it to 16 colours.
I could try this for you but as I don't know what a cross stitch pattern looks like, I don't know how close it'd be.
Readicut do it. The website is www.readicut.co.uk or you can write to them at readicut, Terry Mills, Horbury, West Yorkshire WF4 6HD. Hope this is some help