Half C4 WR have static to C3. If you are in one of those, maybe the solution would to farm static instead. Concidering that EHP/ISK is same / better in C3 .
But I believe there is a way how to configure Rattlesnake with Curator II so it output reasonable amount of DPS with 55 km optimal.
Something like this:
[Rattlesnake, C4 PvE]
Capacitor Flux Coil II
Capacitor Flux Coil II
Damage Control II
Imperial Navy Drone Damage Amplifier
Caldari Navy Ballistic Control System
Imperial Navy Drone Damage Amplifier
Gist X-Type Shield Boost Amplifier
Republic Fleet Large Cap Battery
Pith X-Type X-Large Shield Booster
Adaptive Invulnerability Field II
Adaptive Invulnerability Field II
Republic Fleet Large Cap Battery
Republic Fleet Large Cap Battery
Drone Link Augmentor II
Rapid Heavy Missile Launcher II, Caldari Navy Scourge Heavy Missile
Rapid Heavy Missile Launcher II, Caldari Navy Scourge Heavy Missile
Rapid Heavy Missile Launcher II, Caldari Navy Scourge Heavy Missile
Rapid Heavy Missile Launcher II, Caldari Navy Scourge Heavy Missile
Rapid Heavy Missile Launcher II, Caldari Navy Scourge Heavy Missile
Large Capacitor Control Circuit I
Large Hydraulic Bay Thrusters I
Large Capacitor Control Circuit II
Curator II x2
Hobgoblin II x5
Ogre II x2
Mid-grade Crystal Alpha
Mid-grade Crystal Beta
Mid-grade Crystal Gamma
Mid-grade Crystal Delta
Zainou ‘Gypsy’ CPU Management EE-603
Zainou ‘Snapshot’ Heavy Missiles HM-703
Inherent Implants ‘Squire’ Capacitor Management EM-803
Zainou ‘Deadeye’ Target Navigation Prediction TN-903
Zainou ‘Deadeye’ Rapid Launch RL-1003
should be able to do the job for the price of the paladin hull itself. Output 1000 DPS at 55 km even with reload time concerned. You need to get ammo to your WH more often, yes, but even if you manufacture vanilla missiles it still does 950 DPS with them. More if you are good and switch Damage control to C3-X. It should be able to still face tank any wave in Frontier Command Post but deal over 1000 DPS with home made ammo.