I was looking into it and wanted to get access to the system that was said to have the ship Bright Prospect and settlement that sells them.
I went to merope to get in contact with Taurus Mining Ventures to earn a system permit for Mbooni so I can buy the parts there.
Turned out bright prospect is in Merope right now and is selling them for me.
It just costs blueprints and guardian parts, the wiki suggests for each one I want instead of unlocking it permanantly for purchase.
Can't confirm that yet because I need to go out and get more guardian s.
The weapons were described on the buy screen as doing stuff like plasma chargers burst firing and and shard cannons having more range and a tighter spread, I thought that was cool and want em.