Question: Suggestion?

So I have now completed my 8 weeks to a 5k. Unfortunately, I cannot run a 5k quite yet, but I am still working. Also unfortunately I am now on my own to continue my workouts and training and I have to figure out how to push myself in a realm of activity that I am still completely unfamiliar with. What I have decided is that I will continue to run 3x per week..Monday, Wednesday and Friday. I would also like to ad a cardio something on Saturday that is different from running to add sort of a cross-training element. Does anyone have any ideas? I would like to avoid and aerobics video unless someone has one that they've done that they really love that I wouldn't get bored doing. It would also be great if it nicely coordinated with running. Anyone who has any ideas would be greatly appreciated. Also, I am still trying to build up my time running so what my tenative plan is for that is for Monday to be my "hard" day where I try to add a longer distance and then Wed and Fri will be normal days. An example would be: Monday- 1.7 miles, Wed and Fri- 1.5 miles. Sat-different cardio. Next Monday- 2 miles, Wed and Fri- 1.7 miles and so on. Does that sound reasonable? I figure that Monday would be the best day to do a longer challenge run since I will have had 2 days off of running by then. If anyone has any other suggestions about that, I would appreciate that as well. Happy Monday!