Labby, I recommend that you try an elliptical trainer before you invest in one. Maybe a nearby gym will give you a trial membership so you can see of your knees like it.
The reason I give this caution is because I also have horrible knees - my doctor just assumed that I wanted to schedule a dual replacement when I saw him a while back for another knee problem - and I can't do elliptical trainers. I agree that the knee stress is lower and the leg impact is much lower, but I still can't do them. I can, and do, ride a seated exercise bike at the gym. The different angle reduces knee stress, I suppose. Anyway, that's what I'd do.
Oh, on the Nordic walker? I bought one several years ago and then couldn't use it because my stride is so long that the wooden skis ran off the rails in the back. I almost hurt myself a couple of times before I reluctantly gave it up as a bad idea. Now I ride the bike and lift weights, and I seem to do fine. I still have some pain, but it's more manageable when I exercise regularly.
Although I still get ragged about getting aluminum knees.
