Update
Having played with my Zombie deck a few times now I have made some decisions about its content. Firstly, I want to get rid of the Angel’s Trumpet artifact as although it forces ability strong creatures to attack rather than use their abilities, it also hampers my defensive strategy by forcing me to attack rather than leave blockers. I am thinking of replacing it with either another artifact or enchantment that allows me some way of preventing creatures using their abilities, or with an instant or sorcery that allows me to destroy enchantments – particularly Circle of Protection Black!
I have seen a couple of interesting cards out there, but nothing definitive, so will keep looking and experimenting. Will let you know the outcome ASAP. Any ideas let me know.