I would like to make a flavored buttercream (probably recipies from this site) but my question is, will all buttercreams crust? I want it to so I can use the viva method? Thanks! Does anyone have any suggestions on good flavored buttercream? Chocolate, white chocolate, etc? Thanks!

No not all buttercreams will crust. Especially true buttercreams that use real butter. Mine crusts because I use all shortening. Also, if you add meringue powder it will help it crust as well. I have used the paper towel on mine right after icing and it leaves a nice impression no problem.
good luck.

...about the flavor, I always use almond extract when making mine. Everyone loves it and they always say that my icing is not too sweet.