Those two lenses are most likely the Sigma 18-50mm f/3.5-5.6 DC and 55-200mm f/4-5.6 DC. B&H Photo lists the pair for $239 and the D-Rebel body for $829, so if you've found the same kit for $1000, you're getting a good but still believable deal. The only real trade-off is that these lenses won't work on 35mm film cameras because the image circle is smaller. The same trade-off applies to the 18-55mm kit lens that you can also get along with the Canon D-Rebel body.

If you wanted, you could get the exact same Sigma lenses for the same price for a Nikon body. A Nikon D70 without lens is $1000. You might consider whether the extra $170 for the Nikon solution is preferable to the Canon solution or not.

Another interesting point: the Sigma 55-200mm is an intriguing lens, regardless of whether you go Canon or Nikon. The Sigma is only 11oz heavy (310g) and 3.3" long (85mm). The comparable Canon EF 55-200mm f/4.5-5.6 USM II Autofocus is 10.9oz / 3.8" long for $200 by itself. The closest Nikon seems to be the AF Zoom Nikkor 70-300mm f/4-5.6G. That's only $100, but it's 4.6" long and ~17oz.

None of these lenses are what you might call "pro-quality", but the lighter weight and smaller size makes them more attractive if you need to haul them around.