you can try to activate the random maps in rc6, too - see the wiki for more information - just use the existing mission entries from muission*.ufo in your campaign.ufo file to have more missions.
or fire up the mapeditor and generate new maps :-D (there is also a mapping article in our wiki ;-) )
you can also try the 2.1-dev version from mattn.ninex.info download section if you want to have some new maps (though they are most likely not activated in campaign.ufo) - but note, that this will break savegames from rc6