Your descriptions of models suck. Suck like a vortex. Also, that model sounds like it'd suck, not to mention the lack thereof of an actual REASON to make it. Infact, it just seems like you're spurting out whatever random effing idea comes into your head. Oh, and the Laws of Logic dictate that giant swords cannot be wielded by a single hand
As for the avatar thing, make a picture of it on your computer in the applicable format, make sure it is within the size constraints and then go to avatar settings and upload it