Probably the easiest way for you would be:
1) Upgrade 4.0.6 server to 4.1.4
2) Install 4.1.4 on new server (using temp SRP key) (point to the database that current server is using)
3) Perform a phased migration where you simply drag and drop users from one BES to the other
4) Remove the old server from the DB (and uninstall BES)
5) Replace the temp SRP on the new server with the perm one from the old server
6) Drink fine ale (or lager)
BBAdmin, got any mods to this? I'm a little bit of a fish outta water here