Here are some useful links for church needlepersons:

Ecclesiastical suppliers in the UK who sell fabric:

Watts & Co.
Mary Collings
F.M. Church Supplies
Juliet Hemingray
Croft Design Church Shop
Ormsby of Scarisbrick
Vanpoulles

Wippell's don't, I think, sell fabric, but they have a useful set of information sheets on the fabrics they use for making up vestments

In the US:


Ecclesiastical Sewing


Another collection of useful links:

Anglicans online - vestments