I recently purchased an all-weather cover from
https://www.carcovers.com/ for my 66 K10 Suburban and have been happy with it. Soft fleece lined inner (protect vehicle finish) with silver reflective outer skin (deflects sun, helps keep vehicle cooler). The fit is very good, tight to the vehicle, elastic on the ends is heavy duty and holds well. They offer cable and lock kits as well. I live in the mountains under the redwoods, this cover has stood up to it all so far after 6 months of ownership.