Well the PPL doesn't really matter.
But.....
If you go to the school that you intend to do your CPL with they tend to have a standardised PPL program which will make life easier when you get to IR CPL stage.
The CPL/IR is down to a comment made by the now in another job flybe Q400 fleet manager when he stated he would prefer pilots that had been in the same place and the ability to get a school report.
Now to be honest that's all of a bit of red herring because most of the large company's have been sold a line by the schools to get cadets direct through training programs which has tax advantages.
Most of the advice we can give you today won't be much use by the time you are available for work.
Personally I would get the PPL at a commercial school then do a bit of hour building and get the exams out of the way and then have a look at it again before you sit the final lot of exams.