Two of the three you have posted do not have an opening for the thread. That would drive me crazy. Here is my favorite. It's gone up since I bought mine, but the shipping is still free. When I took a FMQ class at a Janome dealer, the instructor liked my foot better than any they sold or her personal Bernina one.
http://www.april1930s.com/html/slant...y___darni.html