Need help choosing a wide angle lens for d40

Hi. New and learning, so open to thoughts and advice. My wife and I are beginning to play around with photography and are really enjoying it. We each have our own nikon d40 (I know, nothing special - but hey - you need to start somewhere). We share these 3 lenses:

nikon 18-55mm kit lens
nikon 35mm f/1.8g
nikon 55-200mm VR

We are starting to look at finding a nice wide angle lens. Not professional grade, but something we can really enjoy. We don't want to get something inexpensive and then wish we had something nicer. We also don't want to get something nice, and realize we made a poor decision. We are looking primarily at the 12-24mm and the 10-24mm. Any thoughts or advice would be much appreciated. We would like to buy the lens within the next 3-4 months.

We are also hoping to find something that will still autofocus on the nikon d40 - which is why we are drawn to the 2 lenses I mentioned above.

One other question I have - does the angle of view on the 12-24mm f/4 stay at 99degrees? The Nikon website lists the max angle of view as 99, with no minimum. For the 10-24mm, the angle of view ranges from 109-61degrees......

Thanks a lot.

Sigma 10-20 is less expensive, can be bought pre-owned and does a fine job.

Try Tokina 11-16mm 2.8f ... great for landscapes and portraits too

I have theTokina 11-16mm 2.8f also and love it.

thanks for the thoughts. upon closer inspection, i realized that the tokina 11-16 dx2 has a built in auto focus motor (something the original tokina 11-16 didn't). it would probably work well on my d40. I havent really considered that lens because I didnt think it would autofocus. also came across something interesting/weird.......the Sigma 10-20mm retails for around $475 w/1 year warranty in USA. I live in Canada, where the same lens retails for $700 but comes w/10 year warranty. Is it the same lens???.......Is the difference in cost solely due to the warranty or are there differences in the lenses?