Gebber

Ok so I started to get into Digital Photography about a year ago. I am currently using a Cannon S5 IS. I didn't want to spend the money on a DSLR at the time because I wanted to make sure I was going to like photography. Now I am hooked and want to get a little more serious. I am into mostly outdoor/landscapes but also like the action shots too.

I have plans to go to Las Vegas and the Skybridge at the Grand Canyon. So I want to get a new camera before I go. I have been considering the Cannon XSi.

So my questions:

What else is there that is comparable as this or even a little better?

As a beginner to DSLR's would it be better to buy the one with the lens kit or body and a better lens? If purchasing a separate lens what should I look for? I don't want to purchase multiple lenses at first so what would be a good "general purpose" lens?

Thanks for any help