Magic items will be really rare and will never be available for purchase.
People who possess and use magical weapons and armor are people not to be trifled with.
There will, and should, be no notion of a “magic item hunt” unless you’re on some sort of quest to find a particular magic item for some reason.
Magic items may be found among the dead but will most likely be bestowed to others as gifts for bravery or some service.
It’s also likely and acceptable for the Player Characters to give magic items to an especially worthy NPC as a reward for similar service… if this confuses you, it’s fine to ask (in the meta-game), when a situation presents itself, if it’s appropriate to give x, y, or z gift to some NPC. I’ll answer you completely honestly… “No, this service isn’t so grand as to warrant this gift,” or “Yes, that’s completely appropriate to do that.” I’ll never seek to fuck over the PCs in this manner. I want the PCs to be big, badass superheroes, and I want the players to feel that they are. I’m not looking to steal the keys to your batmobile.
A note on Attunement – Some people who are more in touch with magic can attune to more than three items. Some, who are less in touch, can attune fewer than three. It’s unfair; I know. Fair is irrelevant… Deal with it.