Are you sure you really know what you want on your boat Robin? It's strikes me that throughout this thread that you are going to spend more than you paid for the boat. Why do you need to spend a fortune upgrading your nav gear to cruise the Yare and the North sea.? I'm not decrying you Robin, it's just that it having worked in the industry based mainly around Oyster Marine, all these super dooper integrated systems came hand in hand with big integration problems. Keep it simple.