I have a used, black Diamond Back HD truck bed cover with cab guard and lumber rack.
It's about 3 years old. I'm a carpenter and have used it so the lumber rack has a few scuffs.
Not much though. Fuctionally a 10. Cosmetically a 7-8. Cover is tough as nails and a vault.
It fits Tacoma models 2005 - 2015. You would need to get a bed latch with a lock so you can lock it up fully.
As I recall, they are less than $100. I'm thinking $50 and easy to install.
Cover was around $2600 new and I'm looking to get $1200.
It's the best and most secure bed cover out there.
Check out their web site for more info.
I'll see if I can find a picture to post soon.