Concidering your username I would advice you to grind for 5000 gold and buy the Ud avatar, it comes with a complementary Warbanner.
but i brought the avatars just before the banners were added to them and poxbox stopped selling banners after that update and i don't know about the other rune stores or where to even find them
Ah, I did the same thing. Try contacting Cortices. I sent him a message asking about getting banners since I bought the avatars before banners were available. He was able to hook me up with them for free.