In principle, I would suggest that WSO was the best option, based on career prospects and future salary. However, the flying roles available to WSOs are far less diverse than those open to WSOps.
If you are looking for a long-term career with good promotion prospects, there is a very strong argument for choosing WSO. Alternatively, if you want to be a helicopter crewman, with a potential option to commission in the future, I would recommend WSOp.