I'm not sure whether "chav" is a suggestion for "Sharon" or "Tussi" - if it's for "Tussi", it misses the fact that it's a purely female term. Furthermore, when I've heard it used, "chav" carries connotations similar to "Prolo"/"Prolet" (which the wiki article refers to as "a new manifestation of classism").
AFAIK, a "Tussi" can be from any social background (i.e she well might be wearing designer clothing rather than "tat"), and the term refers to how she's done up (see the OP). It also carries the connotation of being a bit of an "airhead", possibly being more concerned with her appearance than anything else.
The BE "Bimbo" is pretty similar, and, with "chav" also a British term, why not go with the one that hits the mark? The way I see it, some bimbos might be chavs, but not all chavs are bimbos.
And "tart" (which can easily be taken to mean prostitute) goes to far - whilst they may be somewhat slutty in appearance, a Tussi is not a Nutte. If they can afford it, they are generally "fashion whores" though :)