TerraN_EmpirE
Tyrant King
Until then, the most likely earliest combat exo suits may look a bit like a throwback to medevil knights, where you have a rider with a powered suite riding into combat on a 2-4 legged mechanical mount.
I find this dubious as the purpose is not to replace the legs of the wearer but to augment them. by adding more legs what you are doing is increasing the amount of power needed by the unit. A Centaur body type would need totally powered rear legs and augmented front legs. It would weigh more, be bulkier and more maintenance heavy.
Generally the issue remains power fortunately we live in the right time for battery research. Rechargeable batteries are popular right now especially with more and more modern vehicles and robotics.
Additionally we need to ask what is the main goal?
Full body augmentation ( Super Suits)
These are units that are augmenting both upper and lower body, these will likely take the longest to develop and have the most power needs. They are the true Spartan Suits.
partial body Augmentation
They only augment the legs and are intended to assist in weight carriage have the most in common with medical and possibly the least bulky.
Unpowered assistance
struts basically shock absorbers.
Power scavenging.
These are worn to actually encumber the wearer. They are used to augment battery power by harvesting it from the wearer.
What ever the case for a powered suit I do agree Special ops would be first to get them.