Hummm...this should have gone into a Graphic Support Section

i dont know about a website for downloading avatars, but if you request something im sure many people on this board will try and help out

i searched google and there are quiet a few...

hxxp://metal.20m.com/wmaavatars.htm
hxxp://www.tcdesign.net/free_clipartavatars.htm
hxxp://www.nutrocker.co.uk/animatedgifs.html
hxxp://www.funnypictureslady.com/avatars/avatars.php

for more search google

also if you go to Deviantart, in the forums there are alot of posts where people will make w/e you want