Bishop's Wordsworth is a nice school, the area is cheaper too so may be that's your answer. I would rather live in Salisbury than Chandlers Ford, but thats just my opinion.
I quite agree - it appears that a nice 4 bed house in Chandlers Ford cost upwards of Â£500k inside Thornden Catchment, whilst a nice town house in Salisbury would be Â£150k less. Winchester is even more expensive. Although renting is much more attractive at the moment
Southampton is not very nice, however, the Meon Valley and the New Forest have some lovely towns
The competition in Salisbury seems to be less than Birmingham - approx 1 in 3 applicants are successful, whereas for King Edwards Aston or Bishop Vesey in Sutton Coldfield the success rate is more like 1 in 8
I am convincing myself that Salisbury would be the best option.