The Starfleet version has a single bank of phasers forward. The civilian version is unarmed. Private purchasers may be able to fit weapons to them "after market" with the appropriate permits.
SI has a small number of them mixed in with both the Starfleet and civilian registered batches for it's own purposes, including use as "Q" ships in disputed zones.
ahh almost didnt notice that single Phaser bank ^_^