Thanks again everyone, some great food for thought there.
I really have no need for the turbo and will most likely get a non-turbo Brooklands, but every now and then I wake up and think a Turbo would be really cool to have. At the end of the day any of these cars will be amazing (as long as I don't buy a ruined one of course).
I can see your point about the SY cars, they do look more iconic. I don't know if it's my age or something, but I want the SZ cars more. There's something about the look of them, I know it's not to everyone's taste but I like the straighter lines and love the individual round headlights. Price wise they seem a bit all over the place at the moment as well, on UK autotrader there seems to be a few around £10k but the rest are £30-40k and above.
I've got a few Mulsanne's on my watch list, they do look pretty good. I think I'm more pulled towards the later cars though.