How secure does it need to be?
What's the main purpose?
Basically 2-3 different styles and 2-3 materials.
Roll-up- flexible for loads
Tri-fold- flexible for loads
1 piece- Looks the best IMO but PITA if you have to haul anything oversize. My sister had one on her F150 and she had to remove probably once a month to haul bikes, bbq, etc
Vinyl- easily can be broke into $
Aluminum- secure $$$$
ABS/ fiberglass- $$$
For my last new truck, I used a tri-fold hard tonneau. It was like a giant trunk that was locked secure, weather tight, and I could fold it up in sections or entirely for hauling different items.
For my '77, I am considering Pros-Pick but I plan to buy a Mar-K tool box so don't know if it will work. Just needs to secure luggage for road trips or car shows but still looks nice.
I plan to buy a hard tri-fold for my CC DRW as I use it for hauling, travel, etc.