High level stuff (i.e. >= 9) should only be available from Guard bases.
This ensures a player RP's correctly, or be stuck using crappy equipment and getting vaped. This goes for freelancers and loners (who won't be PvP'ing anyway under the current rule structure), as well as unaffiliated pirates and PvP ho's (is there a difference?)
As for shield-busters, well they are really only necessary for capship or transport killing. For killing fighters a high-level normal gun does the trick IMOH:D