Saw the Powder7 has new 178cm 21 3.0x on for $549.99 with free shipping. That’s your ski as it’s guaranteed from the Fisher plant and will be the unicorn 2021 flex and weight.
Not a fan of demo bindings in general but you especially don’t want them on a current Candide ski with their unique underfoot flex pattern. Most freeride skis have a “moustache” rocker AND flex pattern where there’s rocker and softer flex in the tip and tail with stiffer flex underfoot. The Candide line has moustache rocker(except for the CT 5.0 that’s flat underfoot) but their flex is stiffer tip and tail than most skis but remains the same flex if not a bit softer underfoot. This allows a more forgiving flex in bumps and off piste but eliminates tip deflection when charging through crud.
A long mounting template Demo binding would add weight, higher stack height and wouldn’t allow the skis natural flex under them. Not to worry on mounting point as the Factions are very good within their 3cm sweet spot range that is easily chosen depending on skier style/size, where it’s used and length of ski chosen vs their size.
Freestyle skiers heavy into switch skiing and park use are at the Candide mark, those that want to drive their ski but still want a playful ski are -1.5cm back and traditional skiers wanting the best float and stability will be -3cm back from the Candide mark. The factory mounts go further back as you move wider in the lineup as the sidecuts become more directional.
For your size, style of skiing, length of 178cm on the CT 3.0, I think a mount of -2cm would be perfect. You’d get the ability to drive the ski, be nice a stable at speed, have good float but still be very playful and have easy turn imitation. If you were a bit larger on that length, I’d put you at -3cm or if you chose the 184cm, I’d move you closer than to -1/-1.5cm mark.
So those skis with Red Attack 13s on a deal(I’ll give you a contact that ships to USA) mounted -2cm and you’re done. Think the red would look great on those skis and would be easier to see in powder.