Hi workerbee....I'm totally sympathetic to your stress. It's a daunting prospect with so much to consider. I haven't moved but I set up life after London to help people in your situation!
I rate buying agents very highly when you are moving to an area where you don't live. They can help with so much, including the most basic of hearing about property before you do which is pretty critical. Also they can save you endless useless visits to properties which aren't right in the first place and are very good at helping you think outside the box in terms of properties you might previous discount.
We have lots who advertise on our website (i'm pretty strict about who is on there to make sure only reputable companies). It's all about the relationships because it's really important you trust them to understand your family needs.
I've got a couple of documents on my site about using buying agents which might be worth you reading. I've linked at the bottom for you.
Also for your area I'd suggest talking to those mentioned below but also definitely check out these guys too.
Stacks, Watership, Scout Bee (Winchester Based) Inclover, Pastures New (New Forest Based). You'll find the good buying agents are more than happy to talk it over with you for no fee because so much depends on you trusting them and getting on (and also they often can't take on more than one search of same criteria so they will want to understand your needs too)
http://www.lifeafterlondon.com/buying-a ... o-they-do/
http://www.lifeafterlondon.com/buying-agents-be-aware/
http://www.lifeafterlondon.com/buyingagents/
http://www.lifeafterlondon.com/wp-conte ... London.pdf
Don't hesitate to drop me a note
bee@lifeafterlondon.com if you want to talk it over.
By the way we've still got one space left at a free half hour session we're organising in Putney - advice on your move. Might be a useful starting place for you. To book in visit
www.lifeafterlondon.com/book (we organise them fairly regularly so if you register on the website you'll hear about them)