D80 autofocus with Sigma lens

[sanjin]

Having read many comments regarding D40X and the lenses issue, I`ve decided to go with D80. Now, some of you have said that D40X can only autofocus with FS lenses.
If I buy D80, I would prefer to get third party lenses, such as Sigma, mostly because of high price Nikkor VR lenses.
Here are the lenses I`m thinking about:

1) Sigma 10-20 mm F4-5.6 EX DC HSM
2) Nikkor AF-S DX Zoom-Nikkor 18-135mm f/3.5-5.6G IF-ED (kit included)
3) Sigma 70-300mm F4-5.6 APO DG MACRO

Now, I know that the first lens, Sigma 10-20 is going to autofocus with D80. My questions are:

1. Will Sigma 70-300mm F4-5.6 APO DG autofocus with D80?
2. Is this lens optically stabilized? If it is not stabilized, then there is a new lens by Nikkor The AF-S VR Zoom-Nikkor 70-300mm f/4.5-5.6G IF-ED, but it is so expensive.
3. Can you recomment me any Sigma lens of 300mm that has optical stabilization in it?
4. Finally, what do you think of Sigma 28-300mm F3.5-6.3 DG Macro lens.

I know I ask for much and I ask many questions. If you know, please try to give me your opinions on either of these questions, so far, it`s really been VERY helpfull. Thank you all