The last old-style Beetle rolled of the production line in Mexico a few weeks ago... there were several articles about it:
www.usatoday.com/news/world/2003-07-30-last-vw-beetle_x.htm
As for new engines, many of us have turned to specialty builders who acquire a case and then custom build the engine with after-market parts.
In my case, I turned to Kurt Mezger in Westchester, PA and have not regretted it for a second. If you want to get it from the horse's mouth, I encourage you to contact him. He has a website at:
www.vintageperformance.net
Hope that helps!