I do a lot of landscapes with my D70 and I'd say all you need apart from the kit lens to get you going are a polarizing filter and a decent tripod (both mentioned above!). I like lenses with stabilizing features, but if I'm going out to take landscapes, I absolutely always take my tripod. Some shots require shutter speeds of more than a second and a tripod is the only way to get that kind of shot with any sharpness. I would be frustrated if I had a potentially really good shot that I couldn't get because I didn't have my tripod.
As far as which camera goes, I would suggest what others have, just try a few and see what feels most comfortable to you. They're all going to be great for what you want to do, so it just comes down to what you like the most. For example, when I was looking a few years ago, there was a pentax that was the lightest and smallest DSLR available at the time. I thought this was great, but when I went to look at one, it was too small for my hands and not at all comfortable. I tried holding the D70 and it fit perfectly. Once I found a few I liked, I went back home and tried to decide which would work best for me.