Unless you are looking to strengthen your application with the classes I would not worry to much about taking them. I have talked to several student who were liberal arts majors and took no business course before entering. While they struggled a bit at first, the schools really look to put you in study groups and an environment to succeed.
If you are looking to improve your applications, then I would suggest choosing a local university and going through their extension program. Another option would be to search larger universities online course catalog. I do not think they method the course is taught in matter (live classroom vs virtual). The one thing I would caution, only do this if you are dead set on focusing on the classes. I think it is worse to take a class and get a bad grade. (Personally if you cannot get an A, I would be hesitant to enroll). You do not want to put across the lack of focus on academics with recent course work.
Just my 2 cents, hope this is helpful.