I'd say it'd depend on your attributes. If you got low BM, there's not much point to dire since you do no damage anyway. All they're good for is being a meatshield. And unless you're a thumper, mobs shouldn't aggro on you anyway since you should be out of range.
If you usually run high BM, then I'd say that dire would be the way to go. Though I have to say I usually don't run high BM unless I go thumper. My bow ranger builds tend to have BM less than 6 at most. Most don't even have more than 3. Maybe other people run different builds, so I guess just go with what's good for your build.
As for pets, depends what you think looks cool. The hyena is pretty good when hearty, big and hulking, same as the croc

Myself, I run a hearty strider since the thing has been with me forever and is as tall as a skyscraper. Though it totally blocks me out in most cutscenes (damn diva bird, stealing my screentime hehe). Also, if you want big pets, go for the tyrian and elonian ones. Seems most of the canthan pets don't really grow that much in size, not compared to the others anyway.