How about the following?
I call it the "Doctor Suit" (alternate name "The Cannibal"), both because it's meant to be a medical battlesuit and because it looks a bit twisted, like one of the Doctor's creations.
Imagine a suit the size of a battlesuit, but it is made out of various robotic arms, legs and skulls.
Those are connected with and supported by various organs (hearts pumping fluid to them, guts and lungs filtering it, eyballs providing sight, synthbones providing support, the wires and electronics that make everything work, etc) that surround the cockpit.
The suit is covered by a few thin, semi-transparent sections of synthskin instead of armour, through which the various pulsating organs can be made out.
Whenever the driver wants to heal someone (be they robot or human), he disconnects and rips out the necessary limbs/organs and then performs surgery to replace whatever is missing from the injured person, essentially cannibalizing himself for parts. But he can also work in reverse, taking the still usable parts of permadead teammates and adding them to his body to be used for spare parts later.
That's the basic idea. I can answer questions about how specific parts will work if you want. I'm just not posting everything to keep it simple.
I've got a few more questions for extra equipment it could have but I just want to see if the basic idea can work for now.
I realise it's not the most efficient design, especially since it gives up most armour, but I think it's fun and looks cool.