If you use a source port it won't require Steam at all.

This is true. Totally forgot about that. No reason to not get it from Steam, then.

You still need the data/game file to use with the source ports.

There is no DRM on any of those old id games on Steam. You can copy the files and run them whenever you want on any PC you want, no Steam or installation required. You can also set them all up with their source ports like GZDoom and such without involving Steam, and you can back those files up and run them without Steam and without installing.

Get the DVD version of Quake 4. It comes with Quake 2 and Ground Zero, and The Reckoning. Actually installing the damned thing on any OS post-XP takes some finagling, involving setting Compatibility modes for the setup splashes from the Task Manager itself, but once you get it, it runs just fine on Vista/7, despite (outdated) reports to the contrary. For some reason, though, the soundtracks are completely absent, just like Steam's version of Hexen 2.

Why can't GoG.com sell ID games and it isn't that hard to ask them to sell their games because I'm willing to buy all of them.