It took me some time to come up with an Amarr fit that would work well against POSes out to 250km. The only standard T1 ship that gets an optimal range bonus with large lasers is the Apocalypse. But the stats just didn't seem that good first time I tried to build a fit.
I've had another go, this time using faction mods for the crucial range boosting mid slots. With Leadership V bonuses this targets to 249 km and optimal is 244 km plus 42 falloff. I didn't look into drugs or implants but it should be possible to cheaply get this to 249+ optimal with synth drugs or a 3% implant. It's cap stable and does 401 dps at that range. Not as powerful as the Raven but ammo is much easier to manage.