The wiki is the place to be for those printers. RIPs won't offer any additional image quality, just workflow improvements like nesting, tiling, cut line marks, etc. In fact, some of the newest RIPs (like ImageNest, Overdrive and Qimage) focus on those features and use the driver for communication with the printer.
Be sure to use the printer's on-board calibration procedure BEFORE profiling your papers. You'll want to continue using the on-board calibration process every 6-12 months to obtain consistency over time, and potentially across head replacements. And for profiling, i1Profiler is the best around. Focus on the Perceptual rendering options in i1P to really get the best color results for your workflow.