Not sure which photo you've seen, but average height and spread 6 metres by 4 metres for the hardiest one, although there's one in a garden nearby that's like a tree and covers and area much bigger than that - but its very old.

Needs full sun and a sheltered position, prefers lighter soil but doesn't seem too fussy, and the only one the RHS list as hardy is Solanum crispum 'Glasnevin' (now called 'Autumnale'). The trouble is, everywhere else lists it as frost hardy, and that's been my experience - if you can get one past its first couple of years, its pretty hardy, but not so much in its first two years. I wouldn't recommend planting this in autumn, but rather, wait and plant in spring, give it 6 months to settle in before its hit by cold.

I have one of these, which is more of a blue than purple and is stunning in flower. It was bought to run rampant through the stalks of an old Leylandii hedge and cover the starkness of it. This it has done admirably, it took until the second year to get going, but recommended soil for this is light and well drained and as we are on clay I wasn't sure it would like it! However being planted beside the half-denuded leylandii this proably dries it out a lot.
It's now heading to the height and spread that Bamboo gave so take care if you do plant it. It needs a lot of support unless you trim it to keep it in check.

Forgot to say that the roots are in dappled shade, but it needs the sun.