|You're not the first to mention the idea, but I'm not aware of anyone actually completing a conversion and then posting the details. One fellow I did exchange emails with said he found nothing in the way of bolt-on sprockets, and everything was going to be custom machined.
If you go that way, note that the curved contour of the back side of the crank's V-belt pulley is important. A curved washer on the back side of the timing belt sprocket, and the curved back side of the V-belt sprocket, form a 'funnel' that guides the timing belt onto it's crank sprocket, and keeps it centered there. Preserve that feature.
Good luck, and let us know how it goes.