The type of clematis will be a factor too, for pruning. I've grown clematis on a low fence by doing as @philippasmith2 describes, but it was wooden with wires attached. What do you mean by a wire fence? Do you mean a mesh, or do you mean like stock fencing round fields?Jasmine isn't hardy here, so I don't grow it, but it does get quite rampant in the right conditions, so you'd need to be sure of where you plant.
How long is the fence? They both get huge. A montana can easily cover about 40 feet trained that way, if not more.
Which jasmine are you thinking of? Winter jasmine is better behaved than the vigorous summer-flowerers, but not scented. There are other clematis which don't need cutting back each year and are less vigorous than C.montana, which as Fairygirl says, is a thug. Clematis alpina or C.macropetala are both beautiful and don't need hacking back.