I have my DirecTV HD dish 100' from the house, not including all of the runs through the house, and I have everything wired with copper coated steel RG6.
I have had no problems what so ever with it.
The one thing you want to check is the maximum frequency that the RG6 is rated for.
Everything I have use is rated for up to 3Gz.
If you can find solid copper for about the same price then I would use that but it is not necessary to pay a huge premimum for solid copper.

Check this site out for RG6 cable and installation tools.

http://search.solidsignal.com/?i=1&i1.x=9&i1.y=17&page=1&q=rg6&site=com&u1=q