Best layer 2 bridge over IP solution ?

[Andrew White]

I'm looking for suggestions to the problem below, any help appreciated !!

I have several offices which use LAT MOP and IPX.  This works over the
existing WAN as it is a combination of bridging and routing (routed IP ).

I would like to move to a pure IP network, but need to transport these
protocols until we can remove them entirely from the network.

Is Vtun and netgraph the way to go ? Or is there a simple more stable/proven
method of achiving this ?

Thanks in advance !!

.Andrew