RE: formula with freerace o race sail ?
You know, Remi does bring up some very good points concerning the FE160, especially since you can probably buy a brand new board for similar price as a used formula board. Although a bit heavier, the FE160 would be more durable overall, and the design remains frozen until December 2008. Despite the slight weight penalty, these other pluses tend to elevate the value of the choice overall. If slalom was your goal, there would no question about wanting the lightest top of the line pro level construction. However, with formula type sailing, I believe that there are so many other important factors that come into play that affect performance. Overall, it's tough to say that the lightest weight would be a silver bullet here.
It's not clear whether you intend to race at all, but with the sail, mast and boom choices you're targeting, you would be right in there for racing FE. Something interesting to think about.
Regarding your sail choice, I have to admit that the AC1 sail highlighted in an earlier thread here was a very attractive looking sail. I was quite impressed with its striking graphic design, and I offered my thoughts at the time. Being curious about the AC2, I tried checking out their website, but unfortunately, I had some trouble doing so. Seems that there is some software incompatibility going on. Yet, if the AC2 is as good looking as the AC1, you'll have a real winner on the beach.