If anyone knows a better lock, let me know. But I guess it's just not possible.
From reading about this quite a lot (and only later finding that pretty much everything I'd researched was duplicated in GA2G's "Locks That Work" thread), the Abloy PL362 and a chain from Almax or Pragmasis.
In the end, this is probably possible with any lock out there... just to remind everyone that you can't have 100% security.
If anyone knows a better lock, let me know. But I guess it's just not possible.
http://www.youtube.com/watch?v=LYv4uq_eML8