On single 29 Scarab what would be the best choice for a 80 + mph with standart lower an standart prop shaft height, what would be the best -1 or -2 in single aplication?

Big single engine boats generally need help carrying the bow.
It really depends on how deep the stock propshaft height is and how much power you have.
With more power, you can go a little higher on the prop.
You could always go with -2 and test spacers to find the optimal.

To hit 80 in a 29 single, I'm guessing you'll need 600-650hp.

The engine is a 468ci with BDS 871 at near 8lbs boost 2x quick fuel marine 850 carb, edelbrock performer rpm marine ported head, hyd roller cam by Bob Madara, daytona sensor 3d map ignition, timing at full boost 33 deg. I have never put it on dyno but with my old 525sc engine the speed was 68-69 mph and max 70 mph in good day. Now it ran 80mph all day and in good day good condition i it 82mph. i am guessing the i am at arond 800hp but it is just a guess.
Prop shaft height with the standard bravo lower is at 7.375 inch below the hull.

You should easily be able to go with -2 lower. The Imco lower design should also help. I wouldn't be surprised if you gained up to 5 mph.