Kinloch Anderson do them but they are pricey - http://www.kinlochanderson.com/shop/...ly-adjustable/

Why don't you try making one. You just need a T-shaped piece of cloth with velcro to fasten the top of the T that goes around your neck. Then get a strip of lace (raid your granny's clothes cupboard or visit second hand shops) about a foot long & six inches wide and sew it onto the bottom part of the T in a kind of zig-zag getting wider as you go down like a cone shape. Hey that sounds really easy - I might even try it myself.

Here is a simple jabot & cuffs just using some old lace curtain material - http://www.peo.gov.au/teachers/toolkit/miy_jabot.pdf