I have being drooling over some Rowan Kidsilk Haze in Marmalade. It is so soft and pretty. The woman at a LYS told me that it does look good knit on larger needles, obviously making a very sheer garment.
I have a Karabella Mohair Wrap pattern that calls for a lace weight mohair, I plan on using the Kidsilk even though it is more of a DK weight. The pattern uses a brioche stitch, but i also googled some other stretchy stitches and found a turkish stitch and a mock turkish stitch (free shawl pattern on Elann) that might look good in the Kidsilk. The shawl on Elann is not rectangular, but you might want to check out the stitch pattern.
I am waiting for Barbara Walkers knitting treasury book from the library. The Vogue Stitchonary might have some good ideas for you also. I haven't seen either of these books in person, but they might be a good place to start.