With the stormrazor changes it is no longer a core item. I haven't looked to much into it but your first item has to be trinity force (or frozen gauntlet if you are doing Tank-plank). The Sheen component it what you need to build first obviously since the on-hit part is applied to your q AND your barrels. Next, I guess I would go either crit, or dead man's plate. Keep in mind that Infinity edge has been changed again, so feel free to build infinity edge after tri-force. Phantom dancer is very strong right now. Crit works well on gangplank because again, Q AND barrels CAN crit. Dead man's is great because you can apply the passive with Q or barrels. When in need of MR I would advise you build spirit visage because it increases healing from W. Sterak's also is not a bad item.