If you're only doing dig neg, and given that you'll be using the IJM PiezoDN system, you might also consider an R1430. You could probably also print on matte papers using K6 curves. If you want to print both glossy and matte papers in addition to dig neg then perhaps the P400.
I regard the carts-on-head printers like the R1430 and P400 as being easier to maintain and also easier to deal within pigment sedimentation in the inks than the ink-lines-and-dampers printers. They do come at a cost of more frequent refilling, which may be an issue for higher volume, regular printers.