I don't know if its posible, but it will be great. you can attach a mp3 file, and its show for download, and you have a media bbcode with a mp3 player. If upload to my host a mp3 file and put the link in the media tag its play, why i can do the same with the mp3 attach? it will be great feature :D
It will be good that you can have the access to flag a member in his profile to a group and not only to supermod or admin. So times you got and spammer that wait for low activity in the board and pos in forums without moderator online, if you can give the option to some group (diferente to supermod) it will be great, so you can set a group with the rigth to banner in the profile group and without all the supermod rigths
Like Pereira say, the files for ip.board are around 30 mb, the greater space is the database. My actual database is around 1.3 gb plus sphinx indexers (around 400 mb more).
Its true that the size of the database depend of a lot of factors (if you purge pos and topics ald), the size of you community, etc...