As far as I'm concerned John, the best place is the subaruvanagon.com list:
subaruvanagon@yahoogroups.com ... but you have to be a member to use that;
so go here to join if you want that avenue:
http://groups.yahoo.com/group/subaruvanagon/

I started looking in this direction last summer and wound up contacting the
usual suspects for conversions, such as Smallcar.com in the Seattle area.
There are a lot of people who are collecting these engines (2.2, 2.5, etc.)
rebuilding them as needed, then putting them up for sale to group members.
There's a market in it and the group is a good place to go to ensure you're
dealing with someone who knows that you need the engine plus the harness
from that same car, in order to ensure proper engine management once
installed. There are also great group resources that can either help you
rebuild your own harness, or send it to them and pay them for that.

Bob Stevens
'87 Westy Syncro
"Passion Fruit"