In case you don't belong to Evey's clematis cubit, you may not know that she's open for business now.
http://www.simplyclems.com/
She has a terrific variety of clems for sale. I have always planted clematis vines in the same planting hole with my climbing roses, but Evey's offering some shorter clematis that can just scamper up a rose shrub or a grandiflora. No need for trellises or pillars. The rose will offer enough support.
I want this thread to have a thumbnail, so I'll add a photo of Romantika climbing up Berries 'n' Cream, even though I don't think Evey's nursery carries Romantika.