Go to all dojos. Go with the one you feel most comfortable at. Neither is better in philosophy or methodogy than the other. It all depends on what you connect with.
Aikikai translate loosely as "Aikido World"...so it means all encompassing of all aikido. Traditionally it refers to Hombu dojo (Aikikai in Japan) which is recognized as O'Sensei's original dojo so to speak. Although I have seen Aikikai used loosely elsewhere so it depends on the context.
Good luck in your journey down the path.