Prime Infrastructure supported devices are listed here.
I don't think the 7700 has staterd shipping quite yet or it is just this month with the first ones. In any case PI does not support it. PI support for wired devices is generally quite weak. This will be changing with 2.0, due out shortly but still for Data Center , DCNM is your most full featured Cisco management offering, followed by Prime LMS and finally by PI.
DCNM will allow you to do most everything management-wise with your Nexus switches - provisioning, visualization, fault management, etc. It also fully manages the storage and unified aspects - something neither PI nor LMS do.
