I agreed, and a few days later a parcel of mixed yarns from Homecrafts arrived!
Exciting! First yarn looks like it has possibilities as the base of my design.
Two quite fine yarns - I like the sparkly green, they'll be good for accents.
Cream and black - hmm, think I know what I'm going to do.
And finally - "WOW!" This is sari silk. According to my friend MrGoogle, it's recycled from leftover sari ends and then respun by hand. The colours are as vibrant as you'd imagine, lots of texture, all different thicknesses throughout the hank. This will be the defining feature of the design.
Now all I have to decide is which of my ideas to choose, and get knitting!