So, I've dusted off my old Quake CD and I've been having a tour down memory lane. What I've realised is that I've never played either of the Mission Packs - Scourge of Armagon, and Dissolution of Eternity. Given that Quake mods are basically .pak files that just get installed in a subdirectory under the /quake directory, am I safe to just buy them off Steam? I'm concerned that they have DRM'ed them somehow. Should I just grab them off GOG to be sure?

As a side note, I never realised how many engines are out there. I started with Quakespasm, and am now trying Darkplaces. Both work really well and are virtually unpack and play. Way back when I originally played, I was happy with the Linux binaries from id, and quakeworld.