I think Grisoft are deliberately leaving room for confusion in the hope you'll BUY the AVG Internet Security which is also version 8 or download the trial.

mrdave's 2nd link should get you the free version 8.
If you need another link this one also offers the free version.
http://free.grisoft.com/ww.download?prd=afe

Apparently some people have found it slows things down compared with the previous free version and have disabled email scanning and refused to install the toolbar, but individually it probably depends on your computer setup.

John