I tried Rush Fit once before, it kicked the shit out of me. Hope it works out for you! It's a great program!
Rush Fit is a nice program, but it's kind of awkward when you can easily follow the program without that much effort and St. Pierre, the UFC champion, keeps telling how hard the exercises are for him
All I wanted was some ideas from professional trainers. Google is nice but I wanted some real informed opinions so that I didn't hurt myself doing this. Between my back and my leg finding a good exercise regimen is kinda tough.
I don't know how trained you are at the moment, but your body stats sound quite "extreme" to me, so I'd suggest to build up your supporting muscles at first and working with your diet before starting to really exercise. To go easy on jour joints with that weight you're at, I'd suggest swimming and aqua-fitness so your body gets used to work again. After a while, depending on your progress, you could do cycling, which is less stressful than running to your knee joints.
Your first goal shouldn't be to lose 70lbs (that can be a longterm goal), but to get used to exercise again. Set yourself several small goals. And when you start your program, do a little less
than you are able to. Don't exhaust yourself in the beginning.
Doing less than being able to gives a psychological motivation, because you know that you've done something and could
have done even more, so you want to continue. Exhausting yourself in the beginning gives you negative feedback, because you'll just feel sore and as you're not yet used to it, you don't want to have that feeling again. After a while you can increase the quantity of your training and at some point, maybe after a month (depending on your progress, how you feel etc.) you can start to train as hard as to exhaust yourself, because when you're used to train exhaustion will make your body free dopamins and endorphins which will give you positive feedback.
So as I said, your first goal should be to get yourself used to exercise. Then later, when you have achieved this, you can think about a specific program for weight loss.