nedd help with sigma vs nikon and wide angle lenses

[photowife]

Hi,
I am searching for a wide angle lense that will be good enough for wedding photography. I prefer to spend under $400. I already have nikon 50mm f/1.7 and nikon 80-200 f2.8. I am looking for something with a wider angle lense now that I have switched to digital. Could you give me any advise on the following lenses.
Sigma 28-70mm f/2.8-4
Sigma 28-105mm f/2.8-4
Sigma 24-70mm f/2.8
Sigma24-135mm f/2.8-4.5
Sigma 20-40mm f/2.8
Or any others that you can recommend. I shoot with available light, so I need a fast lense with a large ap. I am afraid to go to wide angle because I want to avoid any distortion. And I am using it for weddings, so it needs to be a good lense and a consistant performer.
Thanks for the help,
S.

[lightwrangler]

I would at least go to 24mm on the wide end if not 20mm. It doesn't sound like you need the tele end considering what you already own. So a 24-70 or a 20-40 would work, be reasonably sharp and bright. And still be fairly easy to hand hold. I went for a 17-35mm 2.8 Sigma and for the most part I am pleased with it. (for samples see the cloud pictures in the Photo section - Georgia Strait) Remember that a 24mm lens is 36mm equivilant on the S2 and that 17mm is around 25mm - not terribly wide, so there isn't much distortion.

However if you are looking for a general purpose lens my opinion changes somewhat and I would reccomend that you consider lenses in the 24mm to 120mm range (like the Nikon VR) I don't have any experience with the Sigma in this range, but it could be a candidate too. Generally speaking this may not be as good as a specific lens that is in the wide angle range only, and most likely will be much larger and heavier. One of the exceptions to this that I have found is the Tamron 28-200mm which is small and light, but not fast (f4.5 I believe). This is a good time to stop and consider what you want out of this lens and buy appropriately since the range of choices is pretty large. And this is a very personal decision - where I may not find certain aspects of a lens acceptable you may have no problem. So if at all possible, take your S2 down to a good store and try a few on, go home and consider the differences.

[Swampy]

Check out the lens test section as well. There's some good examples for many different lenses already. I'm really happy with my Sigma 24-70mm EX 2.8. I shot my friends wedding (350 shots) exclusivly with this lens and they were really happy with the pics, even though I was just playing and they had a real photographer there.