To avoid duplicating samples, skip installing D-Pro Part1, D-Pro Part2, Rapture Classic and any expansion banks that show in the top level of the Command Center. RPro will copy the all the Cakewalk Sound Center, DPro and Rapture programs (including expansion packs) into its program library so they will play from RPRo.
There is no reason to install the banks again unless you are trying to consolidate everything in RPro. Until RPro is modified to be a drop in replacement for the legacy synths there is little to be gained from consolidation at this time.