Stuart Lee is really far away (I've been there too) he's the other side of Yorkshire, furthest away from us in Scotland lol
I know you like the green cheeks, why not give the gumtree owner a wee call, ask questions etc. you never know he maybe reputable and has handled the babies etc.n
There's no harm in asking questions, just don't be pushed into buying the bird if it doesn't sound right, also if it sounds good, then visit, see the breeder handle the birds etc. ask more questions then follow your head and not your heart and don't part with any cash unless you're buying the bird and taking it with you, I only say this because this breeder is not known to me or any of us and I would hate for you to be scammed. X