The pay-cable channel hopes to attract attention with its bloody, steamy take on the gladiator tale. Green screen helps save some green. The gladiators of ancient Rome may have endured horribly violent lives, but they also saw plenty of overheated sex. At least that's the version of history on display in " Spartacus: Blood and Sand ," a sword-and-sandals epic that Starz, the premium cable network, rolls out Jan.