I happen to like Leslie, I don't think you get any more low impact than that. I like to vary the intensity of my workouts, so her tapes are perfect for a low energy day or if I'm doing strength and want to add a little cardio but don't want to jump or hop. These are great for when I don't feel like working out. Her tapes are pretty easy, but hand weights will definitely add intensity and you can also add hops, bigger movements, etc. I have the WAP and WAP for Abs and an older 2-mile tape that is really fun, and a little more faster paced. She is a little chatty though.
HTH!
By the way, I don't think you need to work out twice a day. You don't want to wear yourself out. I believe exercise should be fun, and I know if I thought I had to exercise twice a day or even every day for that matter, that would not be fun to me.
Don't rush weight loss, slower is healthier. Exercise for your health and to have more energy, something good you do for yourself, not just to lose weight. I think we should enjoy life and fit exercise in, not the other way around. I believe in balance and moderation in all things. Just my opinion. I usually lurk here because I know I am in the minority on this and many other things, but I did want to jump in and offer my opinion this time. I will never be able to get through IMax without modifications, but that's ok. I workout at my level and I feel great. I love variety and Cathe is very high on the "fun" factor, nobody does step better!