I'm not sure if I'm missing something, but the Epson Stylus Pro 9700 is a 4 color printer, designed for printing technical drawings (it also does a great job with film for silk screening). We haven't compared gamuts, but with 1 black (either photo or matte) vs. 3 for the 9800 (black, light black, light light black), I can't imagine that you would get the same black and white tonal range. And, with cyan, magenta and yellow (without their light equivalents), I would guess the same would apply to color printing. Re. saving space, the 9700 is much larger than a 9800 - same frame as a 9900 or 9890, so you won't be saving space either. With or without a RIP, it will more than likely be a step down from the 9800 re. print quality. If you transposed the 9 and 7, you can disregard my print quality comments. Re. size, a 7900 takes about the same amount of space as a 9800.
Tony