The roots need to be kept cool, moist and well-nourished so containers are not the easiest option for clematis. Also, most clematis, in my experience, are not a good choice to cover a fence as the growth is often straggly, spindly and easily damaged. They look best growing through other plants in a natural-looking manner as then the foliage is not very noticeable.

I'd go for the large-flowered hybrids with big star-like pointy-petalled flowers, like Lasurstern, 2 or Hagley Hybrid, 3. Avoid the smaller flowered types like the wishy-washy Comtesse de Bouchaud. The rich velvety deep red or purple ones might do the job as well.

IMO, the only clematis with really good, tropical-looking foliage is C. montana, especially the dark foliage types. They have spectacularly profuse smaller flowers in spring but the foliage lasts all season, and will drape everywhere in huge swags in a mature specimen. They are very big and definitely not suitable for pot culture, though. Also, short-lived or prone to sudden death, in my experience!