Pic #2 is the smallest mirror
All mirrors interchange(with the exception of the power extending mirrors, which you don't have pictured)
Just get a mirror with the same options you have(power/heated) and it will plug right in.
The mirrors in pic 3 are my favorite. I have aftermarket ones on my old style 99, and my 2011 has them from the factory. I like them a lot.
There are a lot of pet peeves I have with the 99-07 trucks that will prevent me from owning one, but the angle of the mirror isn't one of them. I do agree that they look better not angled, but I think GM was trying to mimic the angle of the 03+ headlights.
Edit: I have had great success from
https://www.1aauto.com/. I buy a lot of lights and mirrors from them. I bought the mirrors for my 99 from them about 5 years ago. No issues with them at all.