Clayton Sansbury from Sliver Paddle Boards has a fantastic website site that covers all aspects of building a board. Start to finish and all the steps and questions answered in between with his tutorials.
You can order a kit
Plans printed or PDF
Ready to go together
All the extra bits you will need
Light and strong
He has many tried and true designs to choose from.
But it is his Tutorials section that is just amazing , with so much detail and content in video
Thanks Clayton for all your hard work.