Why are you thinking about the 5000?
The Ren integrates more smoothly into a software/VST based setup, but it still has it flaws. I have the 2500 and the Studio, love working with both. But I hate tracking out from my 2500 into daw and only being able to add fx after I've recorded my beats into daw. With my Studio I still miss some features, but nothing that holds me back of doing the things that I want to do. So those are things to consider when you make you're decision.
Then it's very important to get a decent interface. I hear Apogee Duets are great. I'm very satisfied with my Motu interface. But if you want more hands on controls or want to put multiple pieces of hardware in the mix check out the Mackie Onyx series. The traditional Mackie mixingboards which also can be used as your firewire interface for multitrack recording.
Just as important are studio monitors. I'm not into monitors right now because I'm still cool with the ones I have. But I see most hiphop guys rocking those KRK's.
I don't know if that's your thing, but if I had 10k to spend I would throw in a Moog Little Phatty as well.
