Others may have a differing opinion, but I don't think its so much as which pet is good for questing as which pet abilities are, because I don't think you will get a great pet of any kind in first generation. The first generation pet is just a base, the talents you breed into the line are what will make a best pet.
my goal is to get a pet with unicorn, energizer battery, spell proof and spritely because I hate having to heal during a battle.
You can get the best pets by hatching. It is a little annoying because of the timers and the gold it costs, but trust me the result at the end is worth it. First find the pet which has the talents you want. Hatch with it. The talents wont be perfect, so keep going until you get what you want. That's really all I can suggest. I know of no pets which have maycast and resist and other helpful talents. Hope this helped.
The best pet for questing is an Enchanted Armament. It gives you up to 3 pet sharpened blade cards, which can stack with both regular and sharpened blades! This is really powerful, especially when you don't have access to trained sharpened blades. I got my first armament at Magus level and I have not quested with another pet to date, and I'm a Champion.