I think that it would be apt to have such a ship based on the Defiant Class but helped by Starfleet - to basically defend the Wormhole DS9 and Bajor... since the Defiant (II) can't be everywhere at once.
Andrew
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"Who wouldn't be the one you love
Who wouldn't stand inside your love." - Stand Inside Your Love, The Smashing Pumpkins
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"Yes. I have seventeen brains! And eleven legs. And a pecan."
-Frank Gerratana, March 3, 2000