Had a couple of full structural surveys, similar cost to homebuyer's surveys (if you don't buy through mortgage company), value for money was incredible in comparison but you don't get the all important valuation. Results can be scary but the realistic cost-estimates put things in perspective and stop you getting stung by builders (the scariest sounding fault was estimated at £130 but I'd have guessed at five times that price - stainless steel studs to support a spreading wall).
+1 to Building Design Solutions for structural surveys, not one I've used but I've known happy customers.
Mortgage type surveys:- if its an older property and a straight out of college surveyor it can cause problems, mine didn't understand how a purlined roof worked and wanted a stud wall double joisted as you would for a load-bearing wall under an A-frame. Then there was the stained wall that "must be damp" even though the gauge said otherwise. The absent damp-proof course that likewise passed the gauge because it did exist (liquid tar on sandstone). The failed damp course that was lack of ventilation in a sealed disused building (opened windows for 24 hours and it was "fixed") etc etc
Conveyors:- I couldn't recommend anyone I've used so far, had two that disappeared on holiday at inappropriate moments, one who had wool pull over his eyes and two others who dragged their heels. Since then I've thought I might as well get the cheapest and assume the service can't be any worse than the others so I'd grab the recommend by Uffda above.
Luckily I will probably need either ever again.
In a time of universal deceit - telling the truth is a revolutionary act. George Orwell
When the debate is lost, slander becomes the tool of the loser. Socrates