@Blazer: just because of the bad stories about NP masts in big sizes, I 've bought a 2007 Vapor 11.0 with Gaastra 550 race 100%. My thoughts were like yours now: not to buy a NP in big sizes because of the risks...
Guess what: the gaastra 550 mast broke spontaneously, after a session of half an hour. It was lying on the grass. Beside that part, I like NP sails better but that's a matter of personal feeling. Now i've decided not to go bigger than 10 m2. Still have my X7 5.20 (5 years now) with RS2, that's quality.
For the record: don't want a X9 bigger than 4.60, my 4.90 is an X6 (but 4.00-4.30 and 4.60 are X9)
But back on topic: would go for a V8 with X6 5.20 in your position, of other freeracesail. Because as Jille says, the racesails in sizes around 10 are high wind, and you're looking for a low end sails.