[ ] Inline Deflector (Maximum Warp: -0.4)
[ ] Low-Power Warp Core (Maximum Warp: -0.6)
Sure it won't have a very high maximum warp, but it's efficient cruise speed will still be warp 7 and we can give her a single type 3 thrusters, a single forward phaser, and a single forward rapid torp launcher and we have ourselves a discount patrol ship that punches well above it's weight.
And we keep it dirt cheap so they are built in large numbers. Flood the zone. Make sure everything Starfleet cares about is defended.
Seriously, with just a phaser and a rapid launcher these things can likely 2 on 1 a D7 without losses due to overwhelming maneuverability and burst damage.