Best practice – pages – ACF or inline coding

#3 is fastest, #2 is probably slowest and therefore most expensive, #1 is likely the middle ground.

It’s really a function of budget and update frequency. How often will these pages be updated? Who will be updating them? If it’s you the developer then you build it for yourself or another developer. If it’s a client requirement to be able to update it themselves – well, find out what they mean by ‘update’ (are they planning to merely add/swap out images or add entire new pages?), make this process as smooth for them as possible, and train them.