Wow, super great Terry! I'd wait to say Nice Job until I read it but I have complete faith, so Nice Job! Can't wait to see it.
I think the rest of Emer would be great. Although Artifacts & Lost Technology might be a useful and hopefully quick, diversion from the typical sourcebooks. I figure there's a some already written from the old Addendum that many folks no longer have access to. And I figure it would probably write quicker, and be a bit shorter, then a regional sourcebook.
So my vote went to Emer.