OME does make some nice coils to be sure but I will also x2 the note that the 4" springs are much firmer than their 2.5 coils, and in fact firmer than most 4" coils. While very high quality, the 4" springs are designed for a very heavily loaded and optioned TJ so if you feel that your current coils are too stiff, you aren't likely going to find any relief by switching to the OME springs assuming you are running the same shocks. You also may gain some additional height as the OME 4" coils run tall so, in theory, you could make the ride even more harsh by increasing your control arm angle even more.
I also would attribute more of the ride to your shocks. I run the skyjacker hydros (got them for free) and while they aren't horrible for their price range, they also certainly are nowhere near the performance of a good monotube shock such as the OME's, RE monotubes, Bilsteins, etc.
2003 Jeep TJ- 4" Nth LA, 4.88/ARBs, Rubicrawler, 33's, Savvy Steering, Poison Spyder Armor, etc.