Most of the all in one applications such as iPhoto, Aperture, and Lightroom have very rudimentary noise reduction. Lightroom probably has the best. But if you are just shooting for pleasure and mostly using jpegs, iPhoto is really quite good and inexpensive. If you move up a little, considering your requirements, I would suggest you wait for the new Adobe Elements 6.0 which will be out in the spring, or try Lightroom. Both Lightroom and Aperture have downloadable 30 day trials. Aperture is probably the more mature program with more features, but it is also somewhat more difficult to learn, and it requires a very fast machine with lots of memory and a very fast video card.
Only my opinion. It's worth what you paid for it. Your mileage may vary! ;-}