We currently have 49 different firearms available for us to play and expect to have around ~70 at the start of our Early Release.
These are 49 different firearms, not 49 randomizations of a couple of firearms. That said we will have randomization of firearm stats on enemy loot drops and you will be able to customize most weapons with sights, flashlights, lasers, grips, barrel attachments, stocks and more. Please note not all weapons will have all available customize options as some are specific to the weapon.
We have started creating overview videos of some of the firearms and if you are interested head on over to YouTube to check them out. Memory Illusions' Playlist
For now check this one out.