Welcome Ade,
If you plan to do both qualifications, I suggest that you earn your fixed wing first. The simple reason is that there is a lot of carry over between the two (navigation, weather, airspace, radio work, traffic awareness, and some systems), and it's cheaper by the hour in the plane. Having the basics of being comfortable in the air makes it much more easy to focus on learning the differences in the helicopter. Once you have a fixed wing CPL, you'll find that the rotor wing training goes faster = costs less, and depending upon the nation, the exams are probably abbreviated for the CPLH.
I hold both fixed and rotor wing licenses, and this is what I did. Plus, I could use the plane to fly to the helicopter training!