D40 camera: Nikon 18-135mm or Sigma 18-200mm?

I have a Nikon D40, and as many of you know it has no internal motor to shift the glass…

I'm now hesitating between these 2 lenses: Nikon 18-135 and Sigma 18-200 (which is cheaper).

Any advice and why?

I don't see a Nikon 18-135mm lens.
http://www.nikonusa.com/...index.page

There's a Nikon 18-105mm lens that I own and is excellent. And there's the much more expensive Nikon 18-200mm lens that is highly coveted. Both of these are VR.

The Sigma 18-200mm F3.5-6.3 DC lens does not have image stabilization, so that explains why it is so much cheaper. Image stabilization will give you less blurry pix in low light and long zooms, as much as 4 stops. You get what you pay for.AF-S DX NIKKOR 18-105mm f/3.5-5.6G ED VR - recommended, unless you can afford the AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II.