RE: starting with formula...
Here are your questions!
I will answer each one individually.
1.do i need a carbon extension?because in these days i'm buying a new extension and i thought to buy one which will be good on formula too?
Carbon extensions are very nice, but in my opinion, from what I've seen, they break more often than a good high end aluminum extensions. Spend a bit more money and get a Streamlined extension.
The newer HPL extensions work pretty well also, as do the newer ones from Chinook.
Be sure to get one that fits your existing mast foot. There have been some compatability issues recently, with the Euro Pin extensions.
so if i don't need carbon extension, will 30cm one do good, or i should go with 45cm?
This is completely dependent on what sail and mast combination you use.
For smeo rigs a 30 cm is really a little too long, and a 45 cm is so long it can "over stiffen" the base of the mast to the extent you may have foot batten rotation problems.
So, if your rig needs a tall extension, get the 45 cm. If not, use a 30 cm. If your rig needs no extension, get a stubby that only extends about 15 cm.
2.i'm 95kg surfer, i'm looking for the sail from 8/10 to 15-17knots, and i don't think to compete, how big sail i should buy? 9-10m2 should be good?
This is a tough question to answer.
For any winds < 12 knots, the bigger and more drafty the sail, the easier it will be to plane. Try to stay away from the big formula race sails as they are for racing and are too flat and have a limited amount of draft for recreational early planing use.
For winds over 12 knots, a good free race 8.5 should complement your 9.5 to 11.0 free race "big sail" and give you all the range you need.
3. formula board around 150lt will be fine, or i should look for one around 170 o something like that?
Nearly all true Formula boards are right around 150 liters actual volume, so if you truly want a formula board, and they are all pretty much the same width, I'm not sure you have alot of choices.
are you sure that a good early planing board, like the new Starboard Apollo, wouldn't be a better choice for the type of sailing you want to do?
Formula boards are pretty much "racing machnes" and while they aren't real hard to sail well in light winds, when the wind gets up a bit they can become quite a handful for recreational sailing.
thank you very much
You are most welcome!
Hope this helps,