Reason has quite the easy sample rate conversion.
you can change sample rate while your song is playing, without a hitch!
I did not understand what you were asking about originally, but I'd say with Reason samplerates are not an issue (at least in my experience). So if you do sampling, you'll want the highest samplerate, because it allows the most accurate changes with the least destruction of the sound. In other words a sound that is sampled 96000 times a second is displayed way more accurately than at 44.100 times a second. So if you do any pitching or stretching, the higher samplerates will help the accuracy of the sound.
btw. as far as I understand it is impossible to have different samplerates in Reason at the same time, as it converts everything to session rate on import automatically, plus it always uses the highest bit depth available from your interface.