if the beacon is a symbolic item ( which it is ) - and the intention is not to have an annoying amount of little NPCs on you, - i d say, go for the history of sirius. - its as close to the intended item as an artifact - but won t cause any negative attention from NPCs towards the harvesters.
if however, by roleplay means the beacon is supposed to be "fishy" - i d go for the artifact of course. - but that mainly depends on what other facitons have to say about it. - if the official lawfuls decide that the beacon is something "strange" that needs to be looked at... then artifacts are better suited.
maybe - we can get a load of "roleplay" items in the next modupdate. - stuff that has no profitable value ( like credit cards ) but can be used in a wide range of RP actions. - would love that... but not sure how much a load of new commodities affects the server.