Replying to What Ski Size for the Armada arv 94?

I’m currently thinking of buying the Armada arv 94 but am not sure which size to choose 171cm or 178cm. I’m 174.5cm and weigh 64kg. I would consider myself generally an advanced skier, and in the park a beginner-intermediate (Can do wonky 360s and hitting my first proper rails but progress relatively fast). I ski 70-80% of the time park and the rest off-piste.

Also, should I mount the sky's true center or on the "Freestyle" line?

Any recommendations would be greatly appreciated!