Tom, just in case things are getting a bit confused .... RIPs and profiles for your most comonly used papers will both improve then final prints but one doesn't substitute for the other, they are complementary. If B&W prints are your primary interest then the advice on Roy Harington's QTR RIP is right on, it has a fw less features than the more expensive RIPs but should dramatically improve your output and the cost is absolutely right. For the 2400 the two other RIP choices tht I am familiar with are ColorByte's ImagePrint and the RIP from PowerX. ImagePrint is far more full featured than QTR but many blackand white printers are totally satisfied with QTR. Neither I nor the few others I hace talked with have had as much success wih PowerX as with the other commonly available RIPs.
If you do decide to go with ImagePrint then you will also have available to you a fairly large library of paper profiles that ColorByte has developed specificaly for their RIP, profiles that are quite good. I have never used any of the professional profiing services but I believe they all have their champions and detractors. If you are going to be profiling more than 3 papers then you might want to consider "rolling your own." The necessary hardware for you own paper profiling is not inexpensive (figure ~1000 minimum) but balance that against the cost of commercially produced profiles, wasted paper and ink and it may not seem so high. One caveat though, it may not be completely an exact science, especially with the lower priced, handheld spectrophotometers.
As we all know the entire world of digital printing, from commercial printing systems through our photo efforts, is in its infancy. As with any craft that is just developing there is much for all of us to learn. There is no more a single "right path" to the ultimate" digital print than there is to the "ultimate" print produced in a traditional darkroom.