How to grow Passiflora or Clematis climbers to cover a wide surface area

I have two south facing six feet tall fence panels panels that need covering with climbers. The soil is sandy and free draining, which limits the range of plants that can be used. (That said, a Clematis Etoile Violet is now well established in the garden, though it is well looked after with fertilizer and manure mulches.) 

What is the best way to train a climber to cover a wide area: should I plant it in the middle of the two fence panels and fan it out on both sides, or plant it towards the right and train it to left, i.e., the direction the sun tracks across the sky?

I could plant more Etoile Violet, but a contrast would be nice. Passiflora Constance Elliot comes to mind and it seems to tolerate free draining soils. It's supposed to be vigorous, which would be useful in providing quick cover and as far as I can tell it doesn't have too bushy a habit (an advantage on a narrow border). 

Thanks for any advice!

Edit: I've found references to this plant being not just vigorous, but invasive, apparently throwing suckers and runners several meters from the original plant! Does anyone have any advice on this?