I think danians or mipedians are best to start off with, they can give you a good intro to the less commonly used and generic cards. I use danians mostly, BUT I enjoy using mixed decks the most. They help expand your game and let you see combos in cards more easily.
I would advise against OW, not because it is a bad tribe, but because so many people use it that you might get overshadowed. But all tribes are good :)
Yes, Kepiaan does rock :P
Congratz on Khorror!
Thanks for all the comments guys, remember to check my blog http://danianhall.blogspot.com
i have kepiaan