8x57 to 8x68S?

Is it at all possible to convert a Mauser K98 8x57JS to a 8x68S rifle? If so, how much work (read $$) would it take?

Also, is 8x68S ammo available / easy to reload?

I would say that stretching a standard Mauser by 11mm would be somewhere between expensive and unfeasible. Such things as 8x68 were commonly made on Magnum Mausers.

I don't know about factory ammunition.
Huntingtons has RWS brass, Nick Harvey has load data.