The way I see it players who are in in NPC factions should stick to their weapons and ship in addition to civilian models.
The basic in RP reasoning for this is even if you do manage to get the weapon or a ship, you'd still have to be able to get replacement parts and and people that know how to fix them, which might be difficult to find if you're using something like Bretonian weapons in Rheinland.
Civilian stuff is used exclusively by corporate NPCs and many pirate factions, so parts are widly avalible and al ship mechanics are probably trained with them.
Now if you're a freelancer/merc/generic pirate/generic trader then yes, you can and will have more freedom. But freelancers should atleast try to stick to guns and ships that are readily available in the region where they operate. (in RP anyways, because some ship and gun selling points don't make sense)
