http://www.bethannwilliams.com/
This is the official website for BEth Ann Williams. Her book 'Celtic Quilts' has patterns for quilts in it. Gail's books have designs which can be used for quilts or embellishment on other cloth articles, bags, pillows, clothing etc.
I discovered celtic quilting while on holiday in the USA and borrowed the books from the library. Maybe this could be your first option before buying the books.