Good place to buy a OM603 non "14" head?

[swogee]

I'm looking for a good place to buy an non "14" OM603 head. My 300TDT has a "14" head, but it's not cracked (yet). It does however seem to leak oil around one of the head bolts, so at some point I need to pull the head off and replace the head gasket. I figure if I do that, I may as well replace it with a newer "17" or later OM603 head. Does anyone have any ideas as to what place might be a good source for a new or used head? I have heard Metric motors has complete heads. Typically the Pic'N'Pull yards that have been to usually don't have OM603 motors, and if they do the motor is long gone by the time I get there.

Thanks in advance.

-Steve