Coley, your description is pretty much right on with what I've been reading on various rod-building and fly fishing sites. No one line seems to be the "one" so maybe it is a matter of getting the closest one... or getting a couple and using them for specific styles of fishing the rod.
I've seen the following suggested:
1. 360 grain Skagit head w tips
2. 7wt airflo speydicator
3. Speywerk scandi 27' 330 grain head with fused running line and 10' Rio versatips
4. 8 wt. Rio Atlantic Salmon and Steeelhead with 10' Rio versatips
5. 7 wt. Beulah switch line
If I can even get a close match, the line won't be the limiting factor.
-AP