The Callaway X18 irons are more difficult only because of the bore through element. If you have the tools and experience, it’s not too difficult. the PING Eye 2 are pretty straight forward. Taper tip shafts are required and reshafting should be basic and again, with the right tools and a base level of experience, should be easy to accomplish. The US0110 are not taper tip, so they will not work unless you want to bore out the hosels. Need to find a Taper tip option. Not sure what flex you were needing or the weight you were wanting, but the Recoil 65 and Recoil 80 are taper tip and have similar weight options.