Beef cube steak or roast can be substituted for the top sirloin if desired. I would recommend tenderizing tougher beef with baking soda, a meat tenderizer, or whatever you so choose.
Mushrooms can be added or substituted for onions.
Beef broth can be used instead of flavored chicken broth.
Just about any type of pasta could be used, but egg noodle and elbow pasta are probably best.