Hi Edward,
if you are going to build an IOM l am sure alot of people will agree. Get the plans for an Alternative from Brad Gibson. He designs fantastic boats and you will end up with a boat that will do you proud. His website is bgsailsanddesigns.com or just google bg sails it will come up then go to SHOP and you will find line plans for his Alternative design.
You will need fin bulb and rudder a great place to source these is robot yachts as they have great performance.
Best wishes with your build
Rohan