Obviously the correct answer is to buy the bottles full and drink the contents 🙂 But 500ml soft drink PET bottles also work fine IME (even though everyone says you shouldn’t): also gives you the possible benefit of easily reducing the pressure a bit if you over-prime. I’ve used 2l for ginger beer but not real beer, I would assume they are as good for either. Soft drinks are usually higher pressure than beer and googling suggests that in practice they can hold about 100psi or more.
No problem with clear bottles in a dark room/box.
I guess if you’re paranoid, store the beer somewhere where a blowout won’t matter. But I have never had one (my mother, with wine corks, on the other hand…).