@Corsair
The integrated weapon variant that Nik mentioned is the 2PEW variant Sean's working on. It would implant a large laser blaster thing* in each forearm, at the cost of removing all implanted melee options, and weakening the arms. It's a great option (although I'd still prefer mobility), but the council has basically vetoed it for (poorly thought out >.>) reasons. You can wait for it, but it might not ever exist, so that's probably not a good plan.
*"Blaster thing" means Penetrating Energy Weapon. It's a High Energy Projector modified to be able to fire a beam rather than a cone. This beam can penetrate a battlesuit's armor in one shot, although not an assaultsuit's. Or it can do standard HEP cone shots. Infinite ammo, but can only fire once every minute. Since the suit includes two, you can fire one shot egery thirty seconds.
The difference between analog and MMI interfaces is minor. The MMI makes the cockpit negligibly roomier, and lets you keep your limb inside the central armor ball, rather than inside the suit's less-armored limbs. Since your brain is directly hooked up to the suit, you can operate it at perfect efficiency even if you have no limbs. It also lets you send texts with your mind, even when outside the suit.
Disadvantages of the MMI version are that it takes up an amp slot, meaning you can only have two rather than three, and that allies who don't have an MMI can't pilot it. That might be considered a feature though, because it means it is entirely impossible for an enemy to hijack your assaultsuit.