They’re both approved publishers so I’d recommend both equally. You do however get a 20% discount on the BPP books if you follow the link on the bottom right of the page.
It may be worth asking this question on the general forum for P2 to gauge what other students prefer and why. That might help you make a decision.
At the end of the day success in the exams is not down to which books you use but how you use those books during your studies.
Hope the studying goes well and if you’re ever stuck then please don’t hesitate to ask.