If that’s for a perch, you don’t need to bother with tier or class.
Just use a warrior with the best quality possible, Mythic or if you don’t have one yet Legendary. Your first Mythic Warrior will be Mehaten and he’s Fire, so defensive fire gear should be your main objective.
Why Mythic Warrior? Because it gives a random shield that adds an extra 25% HP to one tower at random and the longer a tower stays alive the more damage it can deal. Also until you unlocked all perches to lv 31 you shouldn’t keep leveling them further than this, that’s a waste of resources and timers and it inflates your level without adding significant power. You shouldn’t chose a higher tier of dragon either unless you have a Mythic and adequate gear for it, because the rise in attack power from the perch is negligible compared to losing 25% HP on a tower which may be the difference between a successful raid or a dead Dragon.
As others have said, quests only require 20-30 min worth of rss, so we don’t need anything that shows us how much there is inside and dragons are sorted by tier in most if not all places.