In additon to the Montblanc, Rockler's Summit and Berea's New Series are also in this general style.
There are also both 7mm and 8mm variants of the European style, so you can make pens with either Cross or Parker style refills. Some of the common names used are: Round Top, Round Top 7mm, Round Top 8mm & Round Top Streamline. These names often include the words European or Euro, but not always.
There are probably others that I can't remember off the top of my head.