Folks,
I bought a house in November in this area and i used Collins Maher Martin. Their website is [broken link removed] although i've just noticed they don't include structural surveys in their services , maybe they've given up that side of the business. Give them a shout anyway, i found them very professional, prompt and wrote a detailed report. I should point out that i'm a first time buyer so i wouldn't have much experience with this stuff and i am in no way connected with their company other than being a satisfied customer. the fee was about 300 quid at the time. Hope this helps!