Short answer - there's little demand for flamenco model, so retailers don't really keeps legit Spainish style flamenco's in stock. I made do with what I could find (A yahama CG171S),
One option would be to chat to Bienyameen - he's pretty much the flamenco guy in SA and occasionally will part with a instrument, they're legit spainish instruments flamenco's but the prices are in Euro's...
I tried quite a few classicals and not much tempted me in the shops - but one locally made one did (see below).
If a locally made one interests - You can try Berg Guitars, Marc Maingaard, Casimi Guitars and Murray Kuun.
Of those, Berg Guitars & Murray Kuun would be my first stops.
The 'best' (taste is so subjective, especially when it comes to nylon stringers), nylon strigner I've played was a 'Colin Rock' parlour nylon guitar - while not specifically a flamenco guitar, it had a Golpeador and just sang. AFAIK he's not a full time luthier (then or now), but trained/worked with the big names locally and made a few (I know of two) guitars.