I should think its going to end up upwards of a grand including the driveshafts and the new flywheel etc, its not a minor change to make.
And probably another 500 for fitting.
If the kits are good, im sure MWM will be keen to fit them as I know they dislike the fragile 172 boxes too!
I think a lot of people are keeping an eye on it with hope it come's off not many like the 172 box. Not bad of a price if its that considering the work that has to go in.