Welcome to the board, Suzanna!!!
Congrats on winning the game AND wanting to replay too!!
Resetting your adventures will not affect your avi files. It will remove your characters class history (so if you had a warrior turned paladin turned samurai it would be possible to become a paladin again); quest items will disappear but little else.
We think that in the original plans for the game (which never made the final release) it was likely that the Zenmaster and Valkyrie class would have become available sooner. Still, they are great classes to play in replaying the game!
Have fun and keep us posted on how your new game is going!!
Wyv