I think there are many more expert GoY-ers than I am, but first thoughts are,
I'd allow approximately 1 permanent plant per metre and fill any empty early gaps with temporary residents for summer, like morning glory, sweet peas, climbing nasturtiums.

For permanent residents I'd include Abutilon megapotamicum as the flowers are so colourful.
Vitis coignetiae
Variegated ivies are always reliable and very useful to brighten up shade
This could be a wisteria opportunity!
Hops? Very vigorous, but at least they die back in winter & give you seasonal variety
Do you think Campsis would have a fighting chance?
Winter jasmine for a bit of winter cheer

I never seem to succeed with clematis - good luck if you can! :-)
I think honeysuckle and virginia creeper may be too thuggish, but you may be able / willing to keep them under control.

id say it depends on the climber realy as bye nature a lot of them are going to half or fully cover your trellis . i dont think in this case thuggish is such a bad thing . all climbers need a bit of atention . how about the smaller veriaty of virhinia creeper or a verigated grape vine .

Actinidia kolomitka, ten foot stems and pink leaves if you plant in the sunny area of your border. Solanum Glasnevin can be grown as a climber has lovely blue potato type flowers. It will probably be semi evergreen in Kent. Passiflora (passion flower) lots of different ones. Personally I would not plant ivy. Honeysuckle again lots of different ones flowering at different times. Chaenomeles my favourites. See my blog on colours of these. I think on a six foot fence you will need some sort of support to get the plants up to the height you want. If you plant plants which could be quite dense nine foot high will cast a lot of shade unless you are on the west side of the fence. Not a problem until it starts to thicken up and be top heavy. Could be expensive to have the professionals in to deal with it long term. Ceanothus with a little support can be grown against a fence. How about an euonymous radicans. planted against the fence it will climb and give you evergreen cover. Good luck sounds like a big project for you. I think Beattie is right about planting distances.

Difficult to answer how many plants you'll need, and the planting distance - if you used Jasmine officinale, for instance, that can make a spread or width from the ground up of 10 feet eventually, with a spread along the trellis at the top (trained in by you) of 30 feet. If you use summer only climbers like Morning Glory for instance, that'll only take up a foot or 2 feet at the base and 3 feet across the top on the trellis. So the decision about how many you need needs to be made once you've decided which ones you'd like.

here here bamboo .

Thanks everyone, its given me some ideas to look at that I wouldnt have thought of. and thanks Bamboo thats sorted the distance out its easy when you know how!

your welcome drc

Will you be able to get up to train plants in at a height of 9'. I am concerned for your safety and it will need pruning annually. If you have the space could you perhaps put in a line of small trees which would give the height without the problems. Deciduous trees will give shelter even in winter by breaking up the wind without needing to worry about height access. Privet if grown as a small tree gives lovely scented flowers. You can have green or golden varieties.

I already have trees along there SG just taking out a few that are over crowding the rest, hence still having some shade. I also have a 9ft deep flower bed in front of the trees with large shrubs in. I dont want to prune the climbers just let them do their own thing. It backs on to fields that are not cultivated. I have some one who comes in twice a year and does high pruning tree work for me, so dont worry with my virtigo I cannot climb anyway lol. The training I can start on horizontal trellis than when it reaches the vertical trellis should run along itself if I choose the right plants?

I'll be interested to see the end product. It is always nice to refresh areas of the garden.

id be tempted to just put a few virginia creepers up and nothing else . they have a great look when they hang down and the are lovley in autumn . the only bit of cutting would be just wear you ca reach .

I will put some pics up when its done Sg. I want to plant several different climbers NP and I think Virginia creeper would swamp the others quite quickly?

yes your right drc726 . it sounds like its going to be nice mind .

I wouldn't use Jasmine officinale either - it'll get to the top of the vertical support and then twine round itself up in the air, not go sideways. Its fair to say that most climbers won't go sideways, they have to be trained or tied in along a horizontal support.
Intrigued by your vertigo reference, Drc - we talking acrophobia or actual vertigo? Actual vertigo is a problem I have...

I have the patience to tie them in Bamboo but will avoid the Jasmine. Yes its vertigo I get dizzy and very nauseous when changing position and fall quite a lot. Its bad when I turn over in bed too. The doc tried me on Histamine that made me so ill I am afraid to try anything else. It started about 7 years ago and varies in the severity though I first noticed I could no longer take heights about 30 years ago. I hate it because when its really bad I must look drunk?

I've PM'd you

Havent got it yet!

i think i mite look into how many different climbers i could reasnably grow round it instead of my first idea of just one . or if you like clemmatis just see how many veriaties i could get on the pagoda . it would be realy interesting after a few years when alol different colour flowers popped out everywear .