I’ll bite on this one...
There are lots of threads on this forum about tonneau covers, you can do some searching and find some really good information that’s already been posted.
I totally agree with you that the roller covers or sometimes called retractable, have the little box that takes up room inside the bed, sucks especially with a truck that has such a small bed.
For me, I really don’t have much of a choice as we need a tonneau cover that has the integrated T-slots so I can put cross bars that mount bikes and toys/gear above the bed of my truck while still being able to use the inside of the bed. Because of that, I’m forced to go with a retractable cover that has the integrated T-slots. Bought the retrax Pro XR and it just showed this weekend and it’s in my garage now waiting to be installed. Got my truck build sheet last Thursday and should have my truck in a couple of weeks if everything goes as planned.
If I didn’t need the integrated T-slots and access to the bed at the same time, it would open up a lot more doors for different types of covers. I personally had really good experience with the trifold Extang heavy duty cover that would hold an insane amount of weight on top of it.
Search the forum threads for others input, lots of good stuff there to learn from.
Have fun!