What rules does the Catholic Church have for venerating crosses/crucifixes on Good Friday?

Each year on the Good Friday service at my parish we venerate the cross, but I really wish it were a crucifix, and I've wondered why we don't have one for that purpose. I've been trying to find one to just drop off at the church with a note saying "this is better, keep it", but before I do, I would like to know if the Catholic Church has any restrictions as to what kind of a cross can be venerated during the Good Friday service? Does the cross have to be a certain size, of a certain material, or are we even allowed to venerate a cross sans-Corpus?