I made a cover for my 26' boat about fifteen years ago. I got my hardware at Sailrite (the grommets, hooks, and the sail thread). Of course I used Sunbrella for the material. I didn't use a kit because I don't like to follow directions. I took the necessary measurements and made the thing from scratch, copying other covers I've seen. I used an inexpensive home sewing machine and I had never sewed before. There were just a couple of places where I had to resort to hand stitching to get through multiple layers of fabric. I'm average handy, and the degree of difficulty of this project was just moderate.
If you haven't sewn before, it sure pays to practice on some scraps and to make a couple simple items like a tiller cover.
I sold that boat about 8 years ago, but I was driving by the marina the other day and saw her for sale again...and it still has the sailcover that I made!