How should Rails models containing database and non-database datasources be broken up?

class Product < ActiveRecord::Base
     has_one :aws_item
  end
  class AWSItem
     belongs_to :product
  end

class Product < ActiveRecord::Base
end
class AWSItem < Product
  def do_amazon_stuff
    ...
  end
end

class Product < ActiveRecord::Base

end

class ItemFetcher < BackgrounDRb::Rails
   def do_work
      # .... Make a cached copy of your ECS catalog here.
      # Copy the Amazon stuff into your local model
   end
end