DIY Wifi Dish

I am trying to build a Wifi dish receptor with a old direct tv satellite, Ive seen several sites with instructions but there very vague and the parts they list are hard to find, if you can please list a site with decent directions and where to find the parts, I found the idea here: http://zip.4chan.org/g/src/1231036720401.jpg
Thank you, if i can do this i can finally drop comcast, I have like a hundred wifi networks near me, Im 2 miles downtown of a major college. Lots of coffee shops.