Replying to Need ALL Your Help With Size

Looking for your suggestions in choosing the length for my new Salomon 1080 Foil, since I won't get a chance to demo different lenghts here in Europe.
I am 5'10", 175 lbs, 28 yo and have been on skis since I started walking.

Currently I ski on 160cm K2 Mach S Comp and 160 K2 Axis X due to mostly skiing short quick turns and I find them both stable enough in higher speeds probably due to my weight. I will be keeping the S Comps for my on-piste skiing and will sell the Axis X's.

Therefore I am choosing between these 2 lengths for the 1080 Foils casue I'm not looking for a bigger radius ski:

a. 166cm, sidecut 124-83-113, radius 15.2m
b. 174cm, sidecut 124-85-114, radius 17.6m

I will be jibbing mostly on-piste doing jumps and some off-piste exploring.
I don't know how twin-tips are compared to normal skis in length due to the tail and (probably) shorter running edge length.

Appreciate all the help!