Okay, here is some available tech:

Advanced solid-projectile weaponry: It will be similar to what we have now, but developed to be a bit more powerful, think the human weapons in the HALO series. 

Early-age interplanetary craft: The story will take place entirely within one star system, and travel between planets will not be fast. However, the craft will be suited for war, in a manner similar to the way ships fought in the Napoleonic era.

Exoskeleton suits: Armor that increases strength, endurance, agility, and speed.

Ancient weapons: Old swords and similar weapons from the old days, made by ancient elven craftsmen, and still, even in this time, are unparalleled in strength 

Now, with that being said, would you rather this be done as a nation roleplay, or individuals within the story?