Go to www.servicehonda.com
and check out their OEM parts selection - they are by far the cheapest place for new parts AND sometimes a new part isn't that expensive (new cyl head for my wife's 2006 CRF250X was only $200).
Also, if you need to replace the cam go with a hotcam OR the old one from my wife's CRF150F might fit (for $cheap).
does the motor still have compression? You also may have bent a valve.