I am not sure how the Part.FCL and UK license aspects work for PPLs. I suggest that you ask wherever you are doing your training. For commercial licenses, you just tick a box on the application form and pay more money! There is no extra training; it is just a paperwork exercise. NB that some of the ratings applicable to a Part.FCL license (eg. aerobatic) are not required on a UK license.
With respect to Annex II aircraft, don't worry at this stage. Simplistically, you need an ATRE rather than a formal type rating for turbine powered aircraft.