Both websites have a selection of shorter Clematis that would suit the height of your mesh fence. A mesh fence would be perfect for training clematis on, provided the fence is well supported.
Life's tragedy is that we get old too soon and wise too late.
It will be fine as longa s you plant it well with plenty of organic matter added to the soil and regular spring feeding to maintain vigour. This clematis only gets to 1.5 to 2m high and all new shoots can be trained horizontally and diagonally to give a good spread across the fence.
It's a group 2 so you just need to dead head and tidy it after it flowers in July and then make sure it doesn't get thirsty in hot or dry spells.
You just need to keep training the new shoots to grow where you want them. That can be a bit of a pain with more vigorous varieties (and new shoots often break while bending them (grr! ), so I would be tempted to plant several of the more recent 'patio' varieties, which have been bred to flower from low down and won't produce a mad tangle of growth if you ignore them for a few days.
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https://thorncroftclematis.co.uk/
It's a group 2 so you just need to dead head and tidy it after it flowers in July and then make sure it doesn't get thirsty in hot or dry spells.
Have to say you would get a longer flowering period from something like this one - http://clematisontheweb.org/new-clemdetail.cfm?dbkey=3738 or http://clematisontheweb.org/new-clemdetail.cfm?dbkey=387 or http://clematisontheweb.org/new-clemdetail.cfm?dbkey=3970 and, being a group 3, means you can cut it back hard in spring and it will grow fresh stems and foliage every year and should produce more flowering stems too if well fed and watered in the growing season.
"We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw