If you are truly looking for quality cover then aurora canvas is the place to go. Price wise they are a littrle more then a tracker/nitro cover but its well worth every penny.
I have had both a Nitro cover and i had an Aurora made for my 882 when i had it and there is a huge difference in quality of both materials and workmanship. I think i paid ~600 for that cover and it never leaked a drop of water and i trailered with it on for a lot of miles.
I want to have them make a cover for my Z7 but they dont have a pattern yet. When i bought my boat i got a civer form th edealer that was made by a custom shop. I like the cover, it fits great but i dont like the materials its made from. It doeasnt breathe and i get condensation in the boat. I am going to send them my cover and let them disect it and make me one just like it from thier materials.