Stage 6 r1400 or polini evo 3 ?

Hello I have a minarelli horizontal LC engine block:
Polini evo 1 pin 12
Artek k2 pin 12 cranck
stage 6 rt intake manifold
Stage 6 26 pwk
Stage 6 double layer air filter
Malossi selettra
Malossi mhr overrange
Stage 6 torque control
Stage 6 RT 433g clutch bell
Stage 6 primary and secondary gears

What exhaust should I choose for this setup?
What squish do you recommend for street use?

Polini evo 1 has a squish of 0,6mm as i remember.
Best exhaust for this cylinder in my opinion is the Yasuni C20 if it’s untuned and the C21 if it’s tuned.