Yeah, the new white MB should do nicely, as hip-hop tends to be somewhat minimal in instrumentation (there are exceptions, of course, as in any genre).
Just make sure you get some decent plug-in effects. If you do notice CPU usage spiking when running several virtual synths (which I don't see happening with this new MB, by the way), bounce some of them to an audio track or two. You'll probably want to do this with the drums anyway, especially if they're sampled. This will open up some CPU time for other instruments.