A quick Wikipedia search - http://en.wikipedia.org/wiki/Caliber_Comics - suggests that Caliver's rights are still owned by Gary Reed. Some titles have been bought up by other publishers, while others are planned as collections or have been reprinted in collections by Transfuzion Publishing and Image. As such I think you'd have great difficulty establishing that any of Caliver's titles are orphaned works - even if they aren't in reprints at the moment, other titles from the label are, so clearly the rights are owned.
You're right on the matter of tracking down and acquiring creator permission - although it needs to be established that the creator is also the rights holder (it's not enough for, say, Warren Ellis to be fine with us posting half of a Nextwave comic like we used to, because the rights holder, Marvel, are the ones who call the legal shots). But if a publisher tells us it's perfectly fine to reproduce a work in its entirety legally, hooray!