If you have the bandwidth, it\'s BETTER to download the mods than to buy them in the retail version. For one, you\'re sure of getting the newest version.
In addition, all the brands of the real life weapons in Counter-Strike were not licensed for that mod because it was started as a free product. When Sierra started selling CS, they had to modify it to change the weapons names to some dorky fictitious names. The downloadable free version still contains all the authentic names.