Ah clowns - the scary part of comedy. And there has to be something scary about grown men and women wearing white face paint and red noses.
Interiors of the mouth - tricky little bugger - what sort of problems are you having with that precisely? Fashioning things like the tongue should be fairly straightforward considering how good your modelling skills are putting together the head. Maybe more prominant bottom teeth to match the top set?
Maybe you can get some ideas here?
http://www.horror-masks.com/ClownsofHorror.html
btw Dave the Gravy's thread was here:
http://forum.simplylightwave.com/sho...&threadid=3603