Hi Nicko,
The 430 is a great boat, I purchased the prototype off Briscat. sure it has Skegs, which gives some performance away, but I've seen it convincingly beat H16's in strong breezes. The design is sound, but if it is not what you want, then build a 430 to your design, and we can call it F430.
The 430 is originally designed as an easy to use fun boat, but they made the rocket version for people like me who want to try and catch Inter 17's (as if!!). The key to the 430 success is the boats' versatility, I can take a Mother who has never helmed before, her daughter who loves to trap on the wire and myself, and the 430 still performs reasonably well, or I can race it single handed and try and catch the demon Inter 17's, which I'm yet to do.
Being a Nacra, you won't have the luxury of going into Nacra sanctioned events, also, you'll have a one off, in which case, you could race against the 430 fleet, but like Darryl Barrett experienced, your boat will be quicker, but a possible class killer. But don't let me put you off building your own, anything to get yourself back on the water!!
Let's face it, "A" class is the prime development class where they are constantly tinkering, F16 is the next rung down the ladder for single handed development class which is a very adaptable boat,i.e. single or 2 up.
My insignificant opinion is that the F16 class is really the one to build into, I know the 430 has rattled some inspiration for an F14 revival, but the AlphaOmega will always wear the crown and to set up another 14' development class is not really warranted.
Chocko