I use Openarena. I have 27 directories each with 200 arena maps. The main pk3s, including HD textures, are symlinked at the bottom of each directory, so they load last. Openarena allows for random map loading if you have a cfg file with the maps names. I made a script to parse the pk3s and generate those files, so I can move stuff around without any real issue. And Testament just fits the game.