The Federation Class is from the Star Trek Technical Manual, written by Franz Joseph. Although there was a falling out between Joseph and Roddenberry, the diagrams from the book were shown on screen during the first six movies, which makes the ships canon in my opinion. That said, there’s no evidence for a refit version, and I’ve altered the designs a bit so I’m sticking them in this category.
Just to add some variation, I made the torpedo launcher much narrower then the Constitution class. I figure it has less ammunition then the larger Constitution, despite the same number of tubes.