I would pick up Doug Fister if I were you. To me, he is the most appealing option because I really dont think that Gorzellany/Garland offers much. Fister has really been pitching well so far and as of the time I am writing this he has 4 no hit innings against Texas.
As for who to drop, I would say Morrow. He shows an awful lot of potential but he would probably be left on the waiver wire untouched for a while if you changed your mind. If you really have an attachment to him, I would say to get rid of Floyd but I do think that he will bounce back.