Converting CMYK to RGB?

Bare with me if this has been covered before.

I am very used to creating CMYK profiles. I know which values need to be on in a spot read of 100% CMYK, etc. The problem comes because it appears as though Colorburst among others is changing over from CMYK RIP to RGB RIP. I guess my question is, what values should I be aiming for in creating good RGB color? What good profiling tools are available? Colorburst no longer includes Spectravision so I can't utilize that and the SpyderPrint just seems a bit too pedestrian and doesn't give me great results.

Any help would be appreciated.