A few times I've used C&C with great success to do Planetary Romance. My formula was CnC+Adamant's Mars + BadAxes's Slavelords of Cydonia + Fate Points = awesome fun!
Personally, I thought that regular D&D style play fit the genre perfectly with a few name changes. Dungeons = Ruins, Magic Items = Forgotten Tech, and Magic = Psionics. Add in the fact that guns are optional anyway and your set.
One time I even had a regualr C&C group teleported to "Mars." The Druid player was ready for a whole campaign. He was ready to bring water to Arrakis.
Slavelords of Cydonia
http://www.badaxegames.com/products/sla ... f-cydonia Mars
http://adamant.rpgnow.com/index.php?cPath=272_4256