Call me crazy, but if your shooting competitively and plan to do so for a few more years, look at a left handed benelli Montefeltro 28". I would add a briley 6oz wieght, throw in the z shims, Limbsaver pad, and add a wolff +25% recoil spring to make it a suitable trap gun. Later on down the road, you can add a removable high trap rib and gel or foam cheek piece. They will cycle just as well as the 1100s with 7/8oz 1150fps loads. Either that, or find a dedicated trap gun. I would probably part out that 1187 and use that compensation for a new gun.
If your in the central VA area, your more than welcome to give my Monte (configured like the above, minus the rib and cheek piece) and Cordoba a run. They are right handed though.