Hi winster,
there are somany ways to do this. we can try this via dynamic action, feature CONTR (you can not defaut coperation field), userexit and Badi,
your requirement is, default contract type and coperation field but you did not mentioned in which event this should happen? when you do personal action like for an example Hiring action and what are the conditions need to be consider when we default the contract type and coperation.
if you still feel confuse or any dificulties then better gp for Badi :HRPAD00INFTY. ask your ABAP'r to develp this for IT0016.
regards,
Dinesh