Alright, so I've got some concepts to throw out here.
The ships I'm currently working on belong to what are colloquially known as the Junkers (since their race name in their own tongue is too tedious to pronounce). Their nickname comes from their instinctive tendency to scavenge just about anything they can lay their hands on; much of their fleet force is made up of ships designed to tear apart chunks of ship wreckage, or weld and make new parts without having to leave the ship. They're about 3 times as large as the average human, weighing in at about a ton each, and their ships fit the scale to boot. Their weaponry systems are mostly railgun-based, to the inclusion of the missile launchers (magnetic propulsion with post-launch ignition). Lasers and plasma warheads are not uncommon, but mostly for point-defense.
The two major Human factions will be fairly obvious: you'll have your generic space-age Human empire, just on the border between Capitalism and Socialism due to a society not yet adjusted to the implications of space travel and extraterrestrial life(we're presuming here that the Human race has carried on its current technological streak, shooting forward past the point of their own evolutionary boundaries), and so straining their government to encompass all of the new minutiae. Technology will be mostly pulsar and laser tech, with a smattering of kinetic force weapons and low-grade railguns.
The other Human faction will be the "browncoats" of our universe, the riff-raff raiders, brigands, thieves, and cutthroats (not necessarily Human, either) that make up the outer rim of Human territory, just barely outside of the reach of the law. Their technology will mostly be kinetic force, as these are cheap, easy to lay hands on, and easiest to integrate into ship mainframes without causing too much trouble. Low-grade lasers will also be relatively common on larger ships.
More to come, since this isn't enough variety. Considering the possibility of an evil biological-based faction not too far from the Tyranid mindset (that is, "EAT IT BECAUSE WE CAN"). Technology there will obviously be mostly corrosive and close-combat based (stomach-plasma suicide bombers?).
"In a mad world, only the mad are sane." - Akira Kurosawa