I reached out to Quaife and they are working on bringing the sequential 5 speed to the IB6 fiesta trans in 2019. I expect it to be priced around $4800, however just stick to roll racing and you'll be fine with an upgraded clutch
Certainly less $$$$$ than all of the Sadev, or X-Trac units out there, or are they considering putting a straight cut/sequential gear set retrofitted INSIDE OF our IB6 cases, the way PPG does with other gearboxes, and hence the 'reasonable' price?
Most of the sidewinder 4 pot sequentials I've ever seen/heard of are under 450 crank HP rated max,
The Global/World RX cars are well north of that figure, but they are all north/south engine and sequentials/AWD systems.