I know, I know, probably late, but I still want to show you how I'd have done the whole infantry system.
For convenient (thought) referencing, using the sand box, free form layout of PS1, to create a similar free form, though a bit more class restricted setup for PS2, in exchange for special abilities. This should encourage more players to carry team support items, thus improving the overall teamwork abilities of groups, particularly small groups who benefit most (where they had no role overlaps, they get some).
In this setup, the shape of the box determines what size objects can fit in, what you can carry in total (yes, Tetris is back!).
Note that I made a separate section for "repair and healing juice". This is the primary advantage of Medics and Engineers: they can carry far more and keep up healing and repairing 3 to 3,5 times longer than other classes. Of course, they also get special abilities, which create advantages for selecting them over the other suits.
In contrast, in this particular example, I've limited the Driver & Pilots to small weapons, but gave them slots for both healing and repairing and slightly more juice than say an HA, plus they get a small surge special ability. Another class that also gets the surge ability is the new Rifleman class. So rather than a shield (which IMO should disable weapon use to make it tactical), they get a sprinting boost like in PS1.
The sniper and infil have been split up into separate suits. As you can see, some units have 4x4 slots and others 3x4 (vertical slots) or 4x3 (horizontal) slots. Most pistols would be 3x3 in size. With adaptions, they might become 4x3 (for instance, with silencer mounted in front). The 3x4 can potentially equip a medical applicator, whereas the 4x3 can equip a repair gun. The sniper class is the only one who would be able to carry the longest and heaviest hitting, most accurate sniper rifles. I would not stop scout sniper rifles from being equiped by other players.
All in all, I think the image is pretty self-explanatory. Any comments, questions and critiques, fire away!
(PS: Did not make one for the MAX yet, being quite a class of its own).