Side Step?
If by running boards, you mean what LR calls Side Steps, the part number is VTK500010 for the LR3; for the Side Protection Tubes, (pipes), it is VTD500010 for Black and VTD500020 for the Stainless pipes.
If you look in a RRSport Kit brochure, it should have the part numbers for the RRS.
I expect that the part numbers will be different as the wheelbase of the Sport is about six inches less than the LR3; 108" vs 113.6" for the LR3. The Sport body length is about 2" less than the LR3's 190.9".