[quote=@Senhara]
<Snipped quote by Yam I Am>

I'm currently spitballing a few ideas but I'm thinking a large shoulder mounted cannon ala Armored Core, but modified for close range usage, then perhaps a medium range kinetic handheld weapon, like an autocannon but less heavy and one handed. Maybe a close range energy shotgun as well? Laser or plasma, mayhaps? Still thinking on this.
[/quote]

Yep, those are all in as defaults thus far.

[quote=@Senhara]
a large shoulder mounted cannon ala Armored Core, but modified for close range usage
[/quote]

Howitzer with the Weapon Slot as your Back Subsystem.

[quote=@Senhara]
a medium range kinetic handheld weapon, like an autocannon but less heavy and one handed. 
[/quote]

Autocarbine, just flavoured however you please. Like, when it mentions 5.6mm, 7.62mm, and 9mm, it's in reference to large rifle rounds just of those calibre. 

[quote=@Senhara]
Maybe a close range energy shotgun as well? Laser or plasma, mayhaps?
[/quote]

I have this as a Plasma Projector: A close-range fan of superheated plasma as a heavy (two-handed) weapon. 

Also, the CAWS, which is like an automatic shotgun that fires Armour-Piercing Incendiary Flechettes.

I think I got you covered in most of those regards for the ideas you have in mind so far, at least.