well, the 147 as std doesnt make the same power or emply the same design parameters so really isnt comparable.
The cams on teh 172 are chill cast and hollow so cost more than normal cams and not everybody can get the blanks to work off.
Cams are available from piper or cat cams, but i dont know the price and its not my place to do research or you.
Will they remap the ECU, sure, if you go to a place that can and you ask them or they recommend it to you.
And exact power figure.....and no varies questions....well thats quite a question! how about x bhp.
But do you really need cams at this point, youll be far better off improving flow and using the std cams as youll gain no real power and just loose some torque running the std inlet manifold.
I really think your outlook on tuning is really warped........its never as simple as your expecting it to be.