I can't really see Halo-tier armor being a thing within this century anyways. Maybe lite cybernetics, but not all the way to Turner's masturbatory efforts.

Bomb Suits will probably be the better base I feel, since in the end they're lower cost and don't have the complex engineering as developing Spartan Armor or T-51 armored suits would bring. Complexity is to welcome failure, so simplicity would be the best in the long-run or while grappling with R+D costs running alongside war-costs.

If a protective shell can be built to naturally compliment the natural power faculties of the soldier in the field and address the major concerns associated with certain combat roles, why try to over-complicate it and introduce more fatal points of failure?

Re-fitted bomb suits would probably give the best ballistic protection at low weight, especially in a world of durable low-weight plastics. At the same time for the sake of mobility you're sacrificing the redundant layers of protection to cushion explosive blasts and prevent internal organ failure associated with such things (like Blast Lung). But you could still probably have someone who can man a light machine gun or safely move ammo between members of the squad in high fire.

But sense the redundant measures have been removed and the suit would still need to be removed quickly for medical treatment, you got enough holes that maybe a well-placed bullet could cripple him, or if he got too close to an exploding grenade or RPG he'd get removed from the field.