I don't think a tiara will be especially bought for Catherine. In this economic climate, it would be bad publicity to buy her a new one, when The Royal Family has so many antique ones.
As for what tiara I would like to see Kate in, the Teck Crescent would be my pick. The Fife Diamond Tiara would also be a great addition, when William is heir apparent. The one tiara I would
not like catheine to get is the Camebridge Lover's Knot
She has to endure enough comparrisons to Diana as it is, and the knot would just be overload
The ring is quite enough.
On another note, I hope its true that Kate will be wearing her hair down on her wedding day. Updos are pretty, but they get boring after a while, plus a tiara with long loose hair can be very eraethral looking. I just hope that if she has her hair down she goes the whole hog, and doesn't have her fringe smoothed back
It defeats the purpose of wearing a tiara with loose hair, if the hair is just flattened out of the way. If you have long hair, either an updo should add to the look, or some flowing locks should. Loose curls, with the Teck Crescent, would make Catherine look wonderful