Skirt wise, a bungee skirt is usually cheaper and easier to get on/off, but usually leaks at least a little water into the boat. Snapdragon and IR make nice ones. Rand skirts are usually more durable, drier, and a more expensive. I have an IR Special K I am very happy with. Snapdragon and Seals also make good ones.
For helmets, WRSI and Shred ready make decent cheaper helmets, just make sure they fit you properly!