| If I were you, I wouldn't download it unless it's a torrent. Believe it or not, torrents can be very trustworthy.
Search the program on isohunt.com. Then, find a torrent for the program that you want that has a +star rating. That's a pretty sure way to make sure it's clean. Also, check the comments and see peoples opinions on it there. I do this for everything I download and haven't found anything bad.
With the scanning part, you might be able to use Winrar, McAffee, AVG, I think Ad-Aware does that sort of thing. You can also use a web based one for smaller downloads like virusscan.jotti.org, but a big download (over 75mb maybe) probably wont work with it and would take a long time.
Hope this helped.
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