[TCattitude]

Check "customavatar" table. There are all customavatars (and "avatar" for you own uploaded avatars for users use as gallery to choose)
There you have an "userid" column to search for userid, and get user's avatar data (filename, size, etc).

BUT... i use avatars as files, not from DB, and have no userful data in there

So i took a quick lookup for what you ask, and... found this:
You only need to check "user" table, and see "avatarrevision" column. If that column is not zero, then user have an avatar, and that avatar is on the server's path that you point on vb's admincp to save them, and have that "revision number" as part of the filename.
Like this example:
If in "user" table for "userid" = 8 his "avatarrevision" is = 2, then his avatar image is:
/server/path/where/avatars/are/stored/avatar8_2.gif

The trick is that filename: avatarUSERID_AVATARREVISION.gif

Hope helps