Emperor: Batttle for Dune mods:
Siege Multiplayer Mod, Dune 2000 Aftermath, Epic Dune, Dune 2000 Advanced, Clash of the Landsraad are very simple/small mods, and you can find them all on FED2k.
Official website: Few.vu.nl
Download: dune2k.com/Download/720 (the download at the official webpage doesn't work correctly because of redirecting, but this link works if you copy paste it to your browser website address [found on dune2k.com/Downloads/39])
A website for Dune fans, which is a must-see one, FED2k: